diff --git a/cmd/opensave-app/frontend/src/App.svelte b/cmd/opensave-app/frontend/src/App.svelte
index 4b614884..f6eec0e9 100644
--- a/cmd/opensave-app/frontend/src/App.svelte
+++ b/cmd/opensave-app/frontend/src/App.svelte
@@ -5,6 +5,7 @@
   import { applyMessage, wsConnected, view, appUpdate, toast, showAbout, cloudOffers, newGames, navigate, settings, games, availableUpdate } from './lib/stores.js';
   import { startController, controllerOn, padUsed, pageStep } from './lib/controller.js';
   import { appearance } from './lib/appearance.js';
+  import { locale, resolveLocale } from './lib/i18n.js';
   import { paletteOpen } from './lib/shortcuts.js';
   import { newlyEmptied } from './lib/emptied.js';
   import { demandAttention } from './lib/notify.js';
@@ -85,6 +86,9 @@
   // with no pointer, it is the only way to see where you are.
   $: controllerActive = controllerOn($appearance.controller, { deviceType: $settings?.deviceType, used: $padUsed });
   $: document.documentElement.dataset.controller = controllerActive ? 'on' : 'off';
+  // The document language follows the chosen locale ('system' resolved); a
+  // wrong lang makes Windows render some Han characters with Japanese shapes.
+  $: document.documentElement.lang = resolveLocale($locale);
   onMount(() =>
     startController({
       isOn: () => controllerActive,
diff --git a/cmd/opensave-app/frontend/src/lib/format.js b/cmd/opensave-app/frontend/src/lib/format.js
index a0647b9e..53e33078 100644
--- a/cmd/opensave-app/frontend/src/lib/format.js
+++ b/cmd/opensave-app/frontend/src/lib/format.js
@@ -1,5 +1,8 @@
 // Small formatters shared by the views.
 
+import { get } from 'svelte/store';
+import { locale, pluralRulesFor } from './i18n.js';
+
 /** Bytes as B, KB, MB or GB, one decimal past bytes: "185 B", "3.2 KB",
  *  "1.4 MB", "9.5 GB". GB so free space on a drive reads as "9.5 GB" and not
  *  "9724.7 MB"; bytes so a small save file is not "0.0 KB". */
@@ -15,8 +18,13 @@ export const fmtSize = (n) =>
 /** A timestamp in the viewer's locale, or a dash for none. */
 export const fmtTime = (t) => (t ? new Date(t).toLocaleString() : '—');
 
-/** "1 game", "3 games". */
-export const plural = (n, word, many = word + 's') => `${n} ${n === 1 ? word : many}`;
+/** "1 game", "3 games". The singular/plural choice goes through the chosen
+ *  locale's Intl.PluralRules (English one/other; other languages get their
+ *  own categories once their views are translated). */
+export const plural = (n, word, many = word + 's') => {
+  const category = pluralRulesFor(get(locale)).select(Number(n ?? 0));
+  return `${n} ${category === 'one' ? word : many}`;
+};
 
 /** How long something was played: "45 min", "3 h", "14 h 20 min". */
 export function playLength(ms) {
diff --git a/cmd/opensave-app/frontend/src/lib/format.test.js b/cmd/opensave-app/frontend/src/lib/format.test.js
index 0db4bb29..28b795e6 100644
--- a/cmd/opensave-app/frontend/src/lib/format.test.js
+++ b/cmd/opensave-app/frontend/src/lib/format.test.js
@@ -1,5 +1,10 @@
 import { describe, expect, it } from 'vitest';
 import { fmtSize, fmtTime, playLength, plural } from './format.js';
+import { locale } from './i18n.js';
+
+// The plural tests assert English wording; pin the language so the suite does
+// not depend on the machine it runs on.
+locale.set('en');
 
 describe('fmtSize', () => {
   it('shows bytes below a kilobyte, KB below a megabyte and MB from one', () => {
diff --git a/cmd/opensave-app/frontend/src/lib/i18n.js b/cmd/opensave-app/frontend/src/lib/i18n.js
new file mode 100644
index 00000000..7c4ca599
--- /dev/null
+++ b/cmd/opensave-app/frontend/src/lib/i18n.js
@@ -0,0 +1,113 @@
+// A tiny, dependency-free i18n layer. `t` is a Svelte store whose value is a
+// translate function: in a component, `$t('key')` re-renders when the user
+// switches language, with no framework wiring.
+//
+// Catalogs live in src/locales/ as flat, dot-keyed JSON. `en.json` is the
+// source of truth: any key missing from another locale falls back to English,
+// so a partial translation never shows a blank. A plural value is an object
+// keyed by Intl.PluralRules categories (`{ "one": …, "other": … }`); Chinese
+// and other single-form languages just use a string.
+//
+// The language choice is 'system' until the user picks one, and only an
+// explicit pick is persisted — so an unpicked app keeps following the OS
+// language as it changes.
+import { writable, derived } from 'svelte/store';
+
+import en from '../locales/en.json';
+import zhCN from '../locales/zh-CN.json';
+
+export const SYSTEM_LOCALE = 'system';
+
+/** The languages offered besides the system default. */
+export const LOCALES = { en: 'English', 'zh-CN': '简体中文' };
+
+const CATALOGS = { en, 'zh-CN': zhCN };
+const FALLBACK = 'en';
+const KEY = 'opensave.locale';
+
+/** A locale id if valid, otherwise null. */
+export function sanitizeLocale(raw) {
+  return typeof raw === 'string' && (raw === SYSTEM_LOCALE || raw in LOCALES) ? raw : null;
+}
+
+/** The saved choice, or 'system' when the user has never picked one. */
+export function loadLocale(storage = globalThis.localStorage) {
+  try {
+    return sanitizeLocale(storage?.getItem(KEY)) ?? SYSTEM_LOCALE;
+  } catch {
+    return SYSTEM_LOCALE;
+  }
+}
+
+/** Persist an explicit pick; 'system' clears it, following the OS again. */
+export function saveLocale(l, storage = globalThis.localStorage) {
+  try {
+    if (l === SYSTEM_LOCALE) storage?.removeItem(KEY);
+    else storage?.setItem(KEY, l);
+  } catch {
+    // Storage refused: the choice lasts until restart.
+  }
+}
+
+/** 'system' settled against the OS language, or the explicit pick itself. */
+export function resolveLocale(l, language = globalThis.navigator?.language) {
+  if (l && l !== SYSTEM_LOCALE) return l;
+  return (language ?? '').toLowerCase().startsWith('zh') ? 'zh-CN' : FALLBACK;
+}
+
+/** The chosen language. Setting it persists immediately ('system' unpersists). */
+export const locale = writable(loadLocale());
+locale.subscribe((l) => saveLocale(l));
+
+/** Plural categories for a locale, as Intl.PluralRules sees them. */
+export function pluralRulesFor(l) {
+  try {
+    return new Intl.PluralRules(l);
+  } catch {
+    return new Intl.PluralRules(FALLBACK);
+  }
+}
+
+/** Look a key up with English fallback, resolve plurals, fill {params}. */
+export function translate(catalog, key, params, rules) {
+  let entry = catalog[key];
+  if (entry === undefined) entry = CATALOGS[FALLBACK][key];
+  if (entry === undefined) return key;
+  if (entry !== null && typeof entry === 'object') {
+    const category = rules.select(Number(params?.n ?? 0));
+    entry = entry[category] ?? entry.other ?? key;
+    // A plural template always mentions {n}; fill it even when the caller
+    // passed no params at all.
+    params = { n: 0, ...params };
+  }
+  if (params) {
+    for (const [name, value] of Object.entries(params)) {
+      entry = entry.replaceAll(`{${name}}`, String(value));
+    }
+  }
+  return entry;
+}
+
+/** The translate function, rebound whenever the language changes. */
+export const t = derived(locale, (l) => {
+  const catalog = CATALOGS[resolveLocale(l)] ?? {};
+  const rules = pluralRulesFor(resolveLocale(l));
+  return (key, params) => translate(catalog, key, params, rules);
+});
+
+/** Split a translated template on its {placeholders}, marking which filled
+ *  parts should render in bold. Returns [{ text, bold }, …] in order. */
+export function segments(template, params = {}, boldNames = []) {
+  const out = [];
+  const re = /{(\w+)}/g;
+  let last = 0;
+  let m;
+  while ((m = re.exec(template))) {
+    if (m.index > last) out.push({ text: template.slice(last, m.index), bold: false });
+    const name = m[1];
+    out.push({ text: String(params[name] ?? m[0]), bold: boldNames.includes(name) });
+    last = re.lastIndex;
+  }
+  if (last < template.length) out.push({ text: template.slice(last), bold: false });
+  return out;
+}
diff --git a/cmd/opensave-app/frontend/src/lib/i18n.test.js b/cmd/opensave-app/frontend/src/lib/i18n.test.js
new file mode 100644
index 00000000..efa936f3
--- /dev/null
+++ b/cmd/opensave-app/frontend/src/lib/i18n.test.js
@@ -0,0 +1,99 @@
+import { describe, expect, it } from 'vitest';
+
+import en from '../locales/en.json';
+import zhCN from '../locales/zh-CN.json';
+import { LOCALES, loadLocale, pluralRulesFor, resolveLocale, sanitizeLocale, segments, translate } from './i18n.js';
+
+// The catalogs are flat, dot-keyed objects; a plural value is one value that
+// must expose an "other" form. Comparing top-level keys is enough.
+const keysOf = (catalog) => Object.keys(catalog);
+
+describe('locale catalogs', () => {
+  it('declares every catalog id in LOCALES', () => {
+    for (const id of ['en', 'zh-CN']) expect(LOCALES[id], id).toBeTruthy();
+  });
+
+  it('has no keys in zh-CN that en.json does not have', () => {
+    const enKeys = new Set(keysOf(en));
+    for (const key of keysOf(zhCN)) expect(enKeys.has(key), `extra key: ${key}`).toBe(true);
+  });
+
+  it('has a zh-CN value for every key in en.json', () => {
+    const zhKeys = new Set(keysOf(zhCN));
+    for (const key of keysOf(en)) expect(zhKeys.has(key), `missing key: ${key}`).toBe(true);
+  });
+
+  it('keeps every value non-empty, and plurals with an "other" form', () => {
+    for (const [catalog, name] of [[en, 'en'], [zhCN, 'zh-CN']]) {
+      for (const [key, v] of Object.entries(catalog)) {
+        if (v !== null && typeof v === 'object') {
+          expect(typeof v.other, `${name}:${key} plural needs "other"`).toBe('string');
+          expect(v.other.trim().length, `${name}:${key}`).toBeGreaterThan(0);
+        } else {
+          expect(typeof v, `${name}:${key}`).toBe('string');
+          expect(v.trim().length, `${name}:${key}`).toBeGreaterThan(0);
+        }
+      }
+    }
+  });
+});
+
+describe('translate', () => {
+  const rules = pluralRulesFor('en');
+
+  it('returns the key itself when nothing has it', () => {
+    expect(translate({}, 'no.such.key', undefined, rules)).toBe('no.such.key');
+  });
+
+  it('falls back to English when the locale lacks the key', () => {
+    expect(translate({ other: 'x' }, 'home.title', undefined, rules)).toBe('Home');
+  });
+
+  it('fills {params}', () => {
+    expect(translate({ k: '{game}: got {count} files' }, 'k', { game: 'Hades', count: 7 }, rules)).toBe('Hades: got 7 files');
+  });
+
+  it('selects plural categories and always keeps an "other"', () => {
+    const catalog = { k: { one: '{n} snapshot', other: '{n} snapshots' } };
+    expect(translate(catalog, 'k', { n: 1 }, rules)).toBe('1 snapshot');
+    expect(translate(catalog, 'k', { n: 3 }, rules)).toBe('3 snapshots');
+    expect(translate(catalog, 'k', undefined, rules)).toBe('0 snapshots');
+  });
+});
+
+describe('segments', () => {
+  it('splits a template into plain and bold parts, in order', () => {
+    expect(segments('open {a} then {b}.', { a: '设备', b: '云备份' }, ['b'])).toEqual([
+      { text: 'open ', bold: false },
+      { text: '设备', bold: false },
+      { text: ' then ', bold: false },
+      { text: '云备份', bold: true },
+      { text: '.', bold: false }
+    ]);
+  });
+});
+
+describe('locale choice', () => {
+  it('rejects unknown locale ids', () => {
+    expect(sanitizeLocale('fr')).toBe(null);
+    expect(sanitizeLocale('zh-CN')).toBe('zh-CN');
+    expect(sanitizeLocale('system')).toBe('system');
+  });
+
+  it("reports 'system' when the user has never picked one", () => {
+    expect(loadLocale({ getItem: () => null })).toBe('system');
+    expect(loadLocale({ getItem: () => 'zh-CN' })).toBe('zh-CN');
+  });
+
+  it('resolves system against the OS language, keeps explicit picks', () => {
+    expect(resolveLocale('system', 'zh-CN')).toBe('zh-CN');
+    expect(resolveLocale('system', 'en-US')).toBe('en');
+    expect(resolveLocale('system', '')).toBe('en');
+    expect(resolveLocale('zh-CN', 'en-US')).toBe('zh-CN');
+  });
+
+  it('survives storage that refuses to read', () => {
+    const storage = { getItem: () => { throw new Error('blocked'); } };
+    expect(loadLocale(storage)).toBe('system');
+  });
+});
diff --git a/cmd/opensave-app/frontend/src/lib/timeline.test.js b/cmd/opensave-app/frontend/src/lib/timeline.test.js
index eb023f07..5b485cd3 100644
--- a/cmd/opensave-app/frontend/src/lib/timeline.test.js
+++ b/cmd/opensave-app/frontend/src/lib/timeline.test.js
@@ -1,5 +1,10 @@
 import { describe as suite, expect, it } from 'vitest';
 import { byDay, describe, filterItems, playedWhere, runs } from './timeline.js';
+import { locale } from './i18n.js';
+
+// The expected titles are English; pin the language so the suite does not
+// depend on the machine it runs on.
+locale.set('en');
 
 const now = new Date(2026, 8, 25, 18, 0);
 const at = (h, m = 0, day = 25) => new Date(2026, 8, day, h, m).getTime();
diff --git a/cmd/opensave-app/frontend/src/locales/en.json b/cmd/opensave-app/frontend/src/locales/en.json
new file mode 100644
index 00000000..7da165a7
--- /dev/null
+++ b/cmd/opensave-app/frontend/src/locales/en.json
@@ -0,0 +1,190 @@
+{
+  "settings.language": "Language",
+  "settings.systemDefault": "System default",
+  "common.cancel": "Cancel",
+  "common.nowTracking": "Now tracking \"{name}\"",
+  "home.addGame.adding": "Adding…",
+  "home.addGame.changeFolder": "Change folder…",
+  "home.addGame.chooseFile": "Choose the save file to track",
+  "home.addGame.name": "Name",
+  "home.addGame.nameHint": "How it shows in your library, and on your other devices.",
+  "home.addGame.namePlaceholder": "e.g. Elden Ring",
+  "home.addGame.savePath": "Save folder or file",
+  "home.addGame.startTracking": "Start tracking",
+  "home.addGame.title": "Track a game",
+  "home.addGame.trackFileInstead": "Track a single file instead…",
+  "home.library.bulkDone": {
+    "one": "{verb} {n} game",
+    "other": "{verb} {n} games"
+  },
+  "home.library.bulkPartial": "{verb} {done} of {total} — {failed}",
+  "home.library.clearFilters": "Clear filters",
+  "home.library.collectionsLabel": "Collections",
+  "home.library.empty": "No games match.",
+  "home.library.emptyFor": "No games match \"{query}\".",
+  "home.library.favourite": "Favourite",
+  "home.library.favouriteTitle": "Add each to Favourites",
+  "home.library.reverseTitle": "Reverse the order",
+  "home.library.reversedTitle": "Reversed — put back in order",
+  "home.library.searchLabel": "Find a game",
+  "home.library.searchPlaceholder": "Find a game…",
+  "home.library.select": "Select",
+  "home.library.selectAll": "Select all ({count})",
+  "home.library.selectedCount": "{n} selected",
+  "home.library.showAll": "Show all",
+  "home.library.showing": "Showing {shown} of {total}.",
+  "home.library.snapshot": "Snapshot",
+  "home.library.snapshotTitle": "Take a snapshot of each",
+  "home.library.sort": "Sort",
+  "home.library.sync": "Sync",
+  "home.library.syncTitle": "Sync each with your devices",
+  "home.library.title": "Library",
+  "home.library.unselectAll": "Unselect all",
+  "home.library.untrackSelected": "Untrack selected",
+  "home.library.verbFavourite": "Added to Favourites:",
+  "home.library.verbSnapshot": "Took a snapshot of",
+  "home.library.verbSync": "Started syncing",
+  "home.library.view": "View",
+  "home.library.viewHint": "Also in Settings → General.",
+  "home.library.viewLabel": "Library view",
+  "home.offered.chooseFolder": "Choose folder…",
+  "home.offered.decline": "Decline",
+  "home.offered.declineToast": "You won't be asked about {name} again. Tracking it yourself later still works.",
+  "home.offered.folderPrompt": "Folder for \"{name}\" on this device",
+  "home.offered.intro": {
+    "one": "Another device syncs this game, but this one doesn't know where to keep it yet. Nothing syncs until you choose.",
+    "other": "Other devices sync these games, but this one doesn't know where to keep them yet. Nothing syncs until you choose."
+  },
+  "home.offered.pathHint": "Kept at {path} on the other device.",
+  "home.offered.title": "Waiting for a folder",
+  "home.offered.trackedToast": "{name} is now tracked here",
+  "home.recent.allActivity": "All activity",
+  "home.recent.empty": "Nothing yet. Snapshots and syncs show up here as they happen.",
+  "home.recent.label": "Recent",
+  "home.scan.alreadyTracked": "Already tracked ({n})",
+  "home.scan.badResponse": "The scan's answer was not a list of saves. Restart OpenSave and scan again.",
+  "home.scan.clear": "Clear",
+  "home.scan.emptyNoMatches": "No matches for this filter.",
+  "home.scan.emptyNothingDetected": "Nothing detected. You can still track any folder manually.",
+  "home.scan.exclude": "Exclude",
+  "home.scan.excludeTitle": "Stop offering this location in future scans",
+  "home.scan.excludeToast": "\"{name}\" won't be offered in scans again.",
+  "home.scan.excluding": "Excluding…",
+  "home.scan.filterPlaceholder": "Filter by name or path…",
+  "home.scan.folderList.headFound": "{name} was found in {n} places.",
+  "home.scan.folderList.headTick": "Tick the folders that belong to this save — they are tracked as one game.",
+  "home.scan.folderList.tagAlt": "another copy — probably an old install",
+  "home.scan.folderList.tagInside": "already inside the folder above",
+  "home.scan.folderList.tagLocation": "part of the same save",
+  "home.scan.folderList.tagSave": "the save folder",
+  "home.scan.folderList.tagTracked": "already tracked",
+  "home.scan.foundInFolders": {
+    "one": "found in {n} folder",
+    "other": "found in {n} folders"
+  },
+  "home.scan.foundSummary": {
+    "one": "Found {n} save location — {m} available to track",
+    "other": "Found {n} save locations — {m} available to track"
+  },
+  "home.scan.foundSummaryEmpty": "Found {n} save locations — {m} available to track, {e} empty hidden",
+  "home.scan.mergedPartialFail": "Tracked \"{name}\", but {n} folder(s) failed: {detail}",
+  "home.scan.oneSave": {
+    "one": "· {n} is one save",
+    "other": "· {n} are one save"
+  },
+  "home.scan.scanningDetail": "Scanning Steam, emulators, and configured folders…",
+  "home.scan.selectAll": "Select all ({n})",
+  "home.scan.showEmpty": "Show {n} empty",
+  "home.scan.showEmptyTitle": "Folders that exist but hold no files — Steam makes one for every game you own, whether or not saves go there. A game with nothing saved anywhere is in here too.",
+  "home.scan.showTracked": "Show tracked",
+  "home.scan.showTrackedTitle": "Also show saves you already track",
+  "home.scan.subScanning": "Scanning your system…",
+  "home.scan.tab.all": "All",
+  "home.scan.tab.emulators": "Emulators",
+  "home.scan.tab.games": "Games",
+  "home.scan.tab.repacks": "Repacks",
+  "home.scan.title": "Scan results",
+  "home.scan.track": "Track",
+  "home.scan.trackAll": "Track all {n}",
+  "home.scan.trackAsOne": "Track as one game",
+  "home.scan.trackAsOneTitle": "Track everything ticked as a single game, whatever it was grouped under. For a split save the scan did not spot.",
+  "home.scan.trackPartialFail": "Tracking \"{name}\" — {n} folder(s) could not be added: {detail}",
+  "home.scan.trackSelected": "Track selected ({n})",
+  "home.scan.tracked": "Tracked",
+  "home.scan.trackedAcrossFolders": "Now tracking \"{name}\" across {n} folders",
+  "home.scan.trackedGames": {
+    "one": "Tracked {n} game",
+    "other": "Tracked {n} games"
+  },
+  "home.scan.trackedGamesWithExtras": "Tracked {n} games with {m} extra locations",
+  "home.scan.type.emulator": "Emulator",
+  "home.scan.type.game": "Game",
+  "home.scan.type.repack": "Repack",
+  "home.setup.chooseWhere": "Choose where",
+  "home.setup.hideTitle": "Hide this guide",
+  "home.setup.later": "Later",
+  "home.setup.noCloudBackup": "No cloud backup",
+  "home.setup.onlyThisDevice": "Only this device for now",
+  "home.setup.pairDevice": "Pair a device",
+  "home.setup.pickFolder": "Pick a folder",
+  "home.setup.progress": "{n} of 3 done",
+  "home.setup.skipped": "Skipped",
+  "home.setup.stepCloud.text": "A copy of every snapshot in Google Drive, OneDrive, Dropbox or a folder of your own.",
+  "home.setup.stepCloud.title": "Back up to the cloud",
+  "home.setup.stepDevices.text": "A PC, a Steam Deck or a handheld with OpenSave on it — on your Wi-Fi, or anywhere over the internet.",
+  "home.setup.stepDevices.title": "Add your other devices",
+  "home.setup.stepSaves.text": "OpenSave looks through Steam, emulators and the usual save folders, and you choose what to keep.",
+  "home.setup.stepSaves.title": "Find your game saves",
+  "home.setup.title": "Get OpenSave set up",
+  "home.summary.cloudBackup": "Cloud backup",
+  "home.summary.cloudBackupTitle": "Open Cloud Backup",
+  "home.summary.cloudNotSetUp": "Not set up",
+  "home.summary.cloudOff": "Off",
+  "home.summary.cloudOn": "On",
+  "home.summary.devicesOnline": "{online} of {paired} online",
+  "home.summary.devicesTitle": "Open Devices",
+  "home.summary.lastSnapshot": "Last snapshot",
+  "home.summary.lastSnapshotTitle": "{name} · {when}",
+  "home.summary.lowSpace": "Only {size} free on the drive your snapshots are kept on — new ones may not fit.",
+  "home.summary.nonePaired": "None paired",
+  "home.summary.noneYet": "None yet",
+  "home.summary.offline": "offline",
+  "home.summary.online": "online",
+  "home.summary.pausedDetail": "Syncing is paused {length}. Snapshots are still taken, and everything catches up when it resumes.",
+  "home.summary.resumeNow": "Resume now",
+  "home.summary.seeSpace": "See what takes the space",
+  "home.summary.sharedSavingTitle": "On disk — {size} less than the snapshots' own sizes, for sharing unchanged files. Open Settings → Storage",
+  "home.summary.spaceUsed": "Space used",
+  "home.summary.spaceUsedTitle": "Open Settings → Storage",
+  "home.tile.inFavourites": "In Favourites",
+  "home.tile.onBranch": "on {branch}",
+  "home.tile.played": "{length} played",
+  "home.tile.snapshots": {
+    "one": "{n} snapshot",
+    "other": "{n} snapshots"
+  },
+  "home.viewOptions.autoFit": "As many as fit",
+  "home.viewOptions.coverStyle": "Cover style",
+  "home.viewOptions.covers": "Covers",
+  "home.viewOptions.fixedNote": "With a set number per row, the tiles share the width between them.",
+  "home.viewOptions.overview": "Show recent activity on Home",
+  "home.viewOptions.tileSize": "Tile size",
+  "home.viewOptions.tilesPerRow": "Tiles per row",
+  "home.chooseFolderDialog": "Choose the save folder to track",
+  "home.cloudBackup": "Cloud Backup",
+  "home.devices": "Devices",
+  "home.scanSaves": "Scan saves",
+  "home.scanSavesTitle": "Look for game saves on this device",
+  "home.scanning": "Scanning…",
+  "home.syncAll": "Sync all",
+  "home.syncAllToast": "Sync triggered for all games",
+  "home.syncPaused": "Syncing is paused",
+  "home.title": "Home",
+  "home.trackFolder": "Track folder",
+  "home.trackFolderTitle": "Pick a save folder or file to track",
+  "home.welcome.hint": "Then open {devices} to pair another PC or Steam Deck, or {cloud} to mirror snapshots online.",
+  "home.welcome.intro": "Keep your game saves in sync across every device — no accounts, no cloud lock-in. Start by finding your saves:",
+  "home.welcome.scanForSaves": "Scan for saves",
+  "home.welcome.title": "Welcome to OpenSave",
+  "home.welcome.trackManually": "Track a folder manually"
+}
diff --git a/cmd/opensave-app/frontend/src/locales/zh-CN.json b/cmd/opensave-app/frontend/src/locales/zh-CN.json
new file mode 100644
index 00000000..12fbb543
--- /dev/null
+++ b/cmd/opensave-app/frontend/src/locales/zh-CN.json
@@ -0,0 +1,169 @@
+{
+  "settings.language": "语言",
+  "settings.systemDefault": "跟随系统",
+  "common.cancel": "取消",
+  "common.nowTracking": "已开始跟踪“{name}”",
+  "home.addGame.adding": "添加中…",
+  "home.addGame.changeFolder": "更换文件夹…",
+  "home.addGame.chooseFile": "选择要跟踪的存档文件",
+  "home.addGame.name": "名称",
+  "home.addGame.nameHint": "它显示在你的游戏库中，也会显示在其他设备上。",
+  "home.addGame.namePlaceholder": "例如：Elden Ring",
+  "home.addGame.savePath": "存档文件夹或文件",
+  "home.addGame.startTracking": "开始跟踪",
+  "home.addGame.title": "跟踪游戏",
+  "home.addGame.trackFileInstead": "改为跟踪单个文件…",
+  "home.library.bulkDone": "已为 {n} 个游戏{verb}",
+  "home.library.bulkPartial": "已为 {done}/{total} 个游戏{verb} — {failed}",
+  "home.library.clearFilters": "清除筛选",
+  "home.library.collectionsLabel": "收藏夹",
+  "home.library.empty": "没有符合条件的游戏。",
+  "home.library.emptyFor": "没有匹配“{query}”的游戏。",
+  "home.library.favourite": "收藏",
+  "home.library.favouriteTitle": "将每个游戏加入收藏",
+  "home.library.reverseTitle": "倒序排列",
+  "home.library.reversedTitle": "已倒序 — 恢复原来的顺序",
+  "home.library.searchLabel": "查找游戏",
+  "home.library.searchPlaceholder": "查找游戏…",
+  "home.library.select": "选择",
+  "home.library.selectAll": "全选（{count}）",
+  "home.library.selectedCount": "已选 {n} 个",
+  "home.library.showAll": "显示全部",
+  "home.library.showing": "显示 {shown}/{total} 个。",
+  "home.library.snapshot": "快照",
+  "home.library.snapshotTitle": "为每个游戏创建快照",
+  "home.library.sort": "排序",
+  "home.library.sync": "同步",
+  "home.library.syncTitle": "将每个游戏与你的设备同步",
+  "home.library.title": "游戏库",
+  "home.library.unselectAll": "取消全选",
+  "home.library.untrackSelected": "取消跟踪所选",
+  "home.library.verbFavourite": "加入收藏",
+  "home.library.verbSnapshot": "创建快照",
+  "home.library.verbSync": "完成同步",
+  "home.library.view": "视图",
+  "home.library.viewHint": "也可以在设置 → 常规中调整。",
+  "home.library.viewLabel": "游戏库视图",
+  "home.offered.chooseFolder": "选择文件夹…",
+  "home.offered.decline": "拒绝",
+  "home.offered.declineToast": "不会再询问你关于 {name} 的事，之后仍可自行跟踪。",
+  "home.offered.folderPrompt": "在本机上为“{name}”选择文件夹",
+  "home.offered.intro": "其他设备正在同步这些游戏，但本机还不知道该把存档放在哪里。选择文件夹后才会开始同步。",
+  "home.offered.pathHint": "在另一台设备上位于 {path}。",
+  "home.offered.title": "等待选择文件夹",
+  "home.offered.trackedToast": "{name} 已在本机开始跟踪",
+  "home.recent.allActivity": "全部动态",
+  "home.recent.empty": "暂无记录。快照和同步会在发生时显示在这里。",
+  "home.recent.label": "最近动态",
+  "home.scan.alreadyTracked": "已跟踪 ({n})",
+  "home.scan.badResponse": "扫描返回的不是存档列表。请重启 OpenSave 后重新扫描。",
+  "home.scan.clear": "清除选择",
+  "home.scan.emptyNoMatches": "没有符合此筛选条件的结果。",
+  "home.scan.emptyNothingDetected": "未检测到任何存档。你仍可以手动跟踪任意文件夹。",
+  "home.scan.exclude": "排除",
+  "home.scan.excludeTitle": "不再在后续扫描中显示此位置",
+  "home.scan.excludeToast": "“{name}”不会再出现在扫描结果中。",
+  "home.scan.excluding": "正在排除…",
+  "home.scan.filterPlaceholder": "按名称或路径筛选…",
+  "home.scan.folderList.headFound": "已在 {n} 个位置中找到 {name}。",
+  "home.scan.folderList.headTick": "勾选属于此存档的文件夹——它们会作为一个游戏来跟踪。",
+  "home.scan.folderList.tagAlt": "另一个副本——可能是旧的安装",
+  "home.scan.folderList.tagInside": "已包含在上面的文件夹中",
+  "home.scan.folderList.tagLocation": "同一存档的一部分",
+  "home.scan.folderList.tagSave": "存档文件夹",
+  "home.scan.folderList.tagTracked": "已跟踪",
+  "home.scan.foundInFolders": "在 {n} 个文件夹中找到",
+  "home.scan.foundSummary": "已找到 {n} 个存档位置——{m} 个可跟踪",
+  "home.scan.foundSummaryEmpty": "已找到 {n} 个存档位置——{m} 个可跟踪，{e} 个空文件夹已隐藏",
+  "home.scan.mergedPartialFail": "已跟踪“{name}”，但有 {n} 个文件夹失败：{detail}",
+  "home.scan.oneSave": "· 其中 {n} 个属于同一存档",
+  "home.scan.scanningDetail": "正在扫描 Steam、模拟器和已配置的文件夹…",
+  "home.scan.selectAll": "全选 ({n})",
+  "home.scan.showEmpty": "显示 {n} 个空文件夹",
+  "home.scan.showEmptyTitle": "这些文件夹确实存在但里面没有文件——Steam 会为你拥有的每个游戏都建一个，无论存档是否放在其中。完全没有存档的游戏也会出现在这里。",
+  "home.scan.showTracked": "显示已跟踪",
+  "home.scan.showTrackedTitle": "同时显示已跟踪的存档",
+  "home.scan.subScanning": "正在扫描你的系统…",
+  "home.scan.tab.all": "全部",
+  "home.scan.tab.emulators": "模拟器",
+  "home.scan.tab.games": "游戏",
+  "home.scan.tab.repacks": "硬盘版",
+  "home.scan.title": "扫描结果",
+  "home.scan.track": "跟踪",
+  "home.scan.trackAll": "跟踪全部 {n} 个",
+  "home.scan.trackAsOne": "作为一个游戏跟踪",
+  "home.scan.trackAsOneTitle": "将勾选的所有文件夹作为一个游戏跟踪，不考虑扫描给出的分组。适用于扫描未能识别的拆分存档。",
+  "home.scan.trackPartialFail": "正在跟踪“{name}”——有 {n} 个文件夹未能添加：{detail}",
+  "home.scan.trackSelected": "跟踪所选 ({n})",
+  "home.scan.tracked": "已跟踪",
+  "home.scan.trackedAcrossFolders": "已跟踪“{name}”，共 {n} 个文件夹",
+  "home.scan.trackedGames": "已跟踪 {n} 个游戏",
+  "home.scan.trackedGamesWithExtras": "已跟踪 {n} 个游戏，并附加 {m} 个位置",
+  "home.scan.type.emulator": "模拟器",
+  "home.scan.type.game": "游戏",
+  "home.scan.type.repack": "硬盘版",
+  "home.setup.chooseWhere": "选择位置",
+  "home.setup.hideTitle": "隐藏此引导",
+  "home.setup.later": "稍后",
+  "home.setup.noCloudBackup": "不做云备份",
+  "home.setup.onlyThisDevice": "暂时只用这台设备",
+  "home.setup.pairDevice": "配对设备",
+  "home.setup.pickFolder": "选择文件夹",
+  "home.setup.progress": "已完成 {n} / 3",
+  "home.setup.skipped": "已跳过",
+  "home.setup.stepCloud.text": "把每个快照的副本存到 Google Drive、OneDrive、Dropbox 或你自己的文件夹里。",
+  "home.setup.stepCloud.title": "备份到云端",
+  "home.setup.stepDevices.text": "一台电脑、一台 Steam Deck 或装有 OpenSave 的掌机——在同一个 Wi-Fi 下，或通过互联网从任意位置连接。",
+  "home.setup.stepDevices.title": "添加你的其他设备",
+  "home.setup.stepSaves.text": "OpenSave 会扫描 Steam、模拟器和常见的存档文件夹，由你选择要跟踪的内容。",
+  "home.setup.stepSaves.title": "找到你的游戏存档",
+  "home.setup.title": "开始设置 OpenSave",
+  "home.summary.cloudBackup": "云备份",
+  "home.summary.cloudBackupTitle": "打开云备份",
+  "home.summary.cloudNotSetUp": "未设置",
+  "home.summary.cloudOff": "已关闭",
+  "home.summary.cloudOn": "已开启",
+  "home.summary.devicesOnline": "共 {paired} 台，{online} 台在线",
+  "home.summary.devicesTitle": "打开设备",
+  "home.summary.lastSnapshot": "最近快照",
+  "home.summary.lastSnapshotTitle": "{name} · {when}",
+  "home.summary.lowSpace": "存放快照的磁盘只剩 {size} 可用空间，新的快照可能存不下。",
+  "home.summary.nonePaired": "未配对",
+  "home.summary.noneYet": "暂无",
+  "home.summary.offline": "离线",
+  "home.summary.online": "在线",
+  "home.summary.pausedDetail": "同步已暂停（{length}）。快照仍会创建，恢复后会自动补齐。",
+  "home.summary.resumeNow": "立即恢复",
+  "home.summary.seeSpace": "查看占用情况",
+  "home.summary.sharedSavingTitle": "磁盘占用比快照自身大小之和少 {size}，因为未变动的文件只存一份。打开设置 → 存储",
+  "home.summary.spaceUsed": "已用空间",
+  "home.summary.spaceUsedTitle": "打开设置 → 存储",
+  "home.tile.inFavourites": "已在收藏中",
+  "home.tile.onBranch": "在 {branch} 上",
+  "home.tile.played": "已游玩 {length}",
+  "home.tile.snapshots": "{n} 个快照",
+  "home.viewOptions.autoFit": "自动排满",
+  "home.viewOptions.coverStyle": "封面样式",
+  "home.viewOptions.covers": "封面",
+  "home.viewOptions.fixedNote": "指定每行数量后，磁贴会平分这一行的宽度。",
+  "home.viewOptions.overview": "在主页显示最近动态",
+  "home.viewOptions.tileSize": "磁贴大小",
+  "home.viewOptions.tilesPerRow": "每行磁贴数",
+  "home.chooseFolderDialog": "选择要跟踪的存档文件夹",
+  "home.cloudBackup": "云备份",
+  "home.devices": "设备",
+  "home.scanSaves": "扫描存档",
+  "home.scanSavesTitle": "查找本机上的游戏存档",
+  "home.scanning": "扫描中…",
+  "home.syncAll": "全部同步",
+  "home.syncAllToast": "已触发全部游戏的同步",
+  "home.syncPaused": "同步已暂停",
+  "home.title": "主页",
+  "home.trackFolder": "跟踪文件夹",
+  "home.trackFolderTitle": "选择要跟踪的存档文件夹或文件",
+  "home.welcome.hint": "然后打开 {devices} 配对另一台电脑或 Steam Deck，或打开 {cloud} 将快照镜像到云端。",
+  "home.welcome.intro": "让你的游戏存档在所有设备间保持同步——无需账号，不被云端绑架。先找到你的存档：",
+  "home.welcome.scanForSaves": "扫描存档",
+  "home.welcome.title": "欢迎使用 OpenSave",
+  "home.welcome.trackManually": "手动跟踪文件夹"
+}
diff --git a/cmd/opensave-app/frontend/src/views/Home.svelte b/cmd/opensave-app/frontend/src/views/Home.svelte
index bcfd5091..de8ecef4 100644
--- a/cmd/opensave-app/frontend/src/views/Home.svelte
+++ b/cmd/opensave-app/frontend/src/views/Home.svelte
@@ -14,6 +14,7 @@
   import PauseButton from '../components/PauseButton.svelte';
   import { setupState, setupSteps, decideSetupFor } from '../lib/setup.js';
   import { settings } from '../lib/stores.js';
+  import { t, segments } from '../lib/i18n.js';
   import ScanSearch from 'lucide-svelte/icons/scan-search';
   import RefreshCw from 'lucide-svelte/icons/refresh-cw';
   import FolderPlus from 'lucide-svelte/icons/folder-plus';
@@ -49,7 +50,7 @@
       showAdd = true;
       return;
     }
-    const dir = await native.selectDirectory('Choose the save folder to track');
+    const dir = await native.selectDirectory($t('home.chooseFolderDialog'));
     if (dir) {
       addPath = dir;
       showAdd = true;
@@ -70,7 +71,7 @@
     for (const g of $gameList) {
       api.post(`/api/games/${g.id}/sync`).catch(() => {});
     }
-    toast('Sync triggered for all games');
+    toast($t('home.syncAllToast'));
   }
 
   // Where each game's save stands — the summary and the cards read the same
@@ -101,14 +102,14 @@
 </script>
 
 <div class="head">
-  <h2 class="page-title">Home</h2>
+  <h2 class="page-title">{$t('home.title')}</h2>
   <div class="head-actions">
-    <button class="btn primary" on:click={() => scanner.start()} disabled={scanning} title="Look for game saves on this device">
-      <ScanSearch size={16} />{scanning ? 'Scanning…' : 'Scan saves'}
+    <button class="btn primary" on:click={() => scanner.start()} disabled={scanning} title={$t('home.scanSavesTitle')}>
+      <ScanSearch size={16} />{scanning ? $t('home.scanning') : $t('home.scanSaves')}
     </button>
-    <button class="btn" on:click={syncAll} disabled={$gameList.length === 0 || $syncPause.paused} title={$syncPause.paused ? 'Syncing is paused' : ''}><RefreshCw size={15} />Sync all</button>
+    <button class="btn" on:click={syncAll} disabled={$gameList.length === 0 || $syncPause.paused} title={$syncPause.paused ? $t('home.syncPaused') : ''}><RefreshCw size={15} />{$t('home.syncAll')}</button>
     <PauseButton />
-    <button class="btn" on:click={trackFolder} title="Pick a save folder or file to track"><FolderPlus size={16} />Track folder</button>
+    <button class="btn" on:click={trackFolder} title={$t('home.trackFolderTitle')}><FolderPlus size={16} />{$t('home.trackFolder')}</button>
   </div>
 </div>
 
@@ -127,15 +128,19 @@
 {:else if $visibleGames.length === 0}
   <div class="welcome">
     <div class="welcome-icon"><Gamepad2 size={34} strokeWidth={1.6} /></div>
-    <h3>Welcome to OpenSave</h3>
-    <p>Keep your game saves in sync across every device — no accounts, no cloud lock-in. Start by finding your saves:</p>
+    <h3>{$t('home.welcome.title')}</h3>
+    <p>{$t('home.welcome.intro')}</p>
     <div class="welcome-actions">
       <button class="btn primary" on:click={() => scanner.start()} disabled={scanning}>
-        <ScanSearch size={16} />{scanning ? 'Scanning…' : 'Scan for saves'}
+        <ScanSearch size={16} />{scanning ? $t('home.scanning') : $t('home.welcome.scanForSaves')}
       </button>
-      <button class="btn" on:click={trackFolder}><FolderPlus size={16} />Track a folder manually</button>
+      <button class="btn" on:click={trackFolder}><FolderPlus size={16} />{$t('home.welcome.trackManually')}</button>
     </div>
-    <p class="welcome-hint">Then open <strong>Devices</strong> to pair another PC or Steam Deck, or <strong>Cloud Backup</strong> to mirror snapshots online.</p>
+    <p class="welcome-hint">
+      {#each segments($t('home.welcome.hint'), { devices: $t('home.devices'), cloud: $t('home.cloudBackup') }, ['devices', 'cloud']) as part}
+        {#if part.bold}<strong>{part.text}</strong>{:else}{part.text}{/if}
+      {/each}
+    </p>
   </div>
 {:else}
   {#if showGuide}
diff --git a/cmd/opensave-app/frontend/src/views/home/AddGameCard.svelte b/cmd/opensave-app/frontend/src/views/home/AddGameCard.svelte
index 9b9952b3..8c95beed 100644
--- a/cmd/opensave-app/frontend/src/views/home/AddGameCard.svelte
+++ b/cmd/opensave-app/frontend/src/views/home/AddGameCard.svelte
@@ -13,6 +13,7 @@
   import { navigate, toast } from '../../lib/stores.js';
   import { api, native } from '../../lib/api.js';
   import { folderName } from '../../lib/filedrop.js';
+  import { t } from '../../lib/i18n.js';
 
   const dispatch = createEventDispatcher();
 
@@ -45,7 +46,7 @@
   onMount(() => nameInput?.focus());
 
   async function pickFolder() {
-    const dir = await native.selectDirectory('Choose the save folder to track');
+    const dir = await native.selectDirectory($t('home.chooseFolderDialog'));
     if (dir) {
       typed = false;
       path = dir;
@@ -53,7 +54,7 @@
   }
 
   async function pickFile() {
-    const file = await native.selectFile('Choose the save file to track');
+    const file = await native.selectFile($t('home.addGame.chooseFile'));
     if (file) {
       typed = false;
       path = file;
@@ -65,7 +66,7 @@
     adding = true;
     try {
       const game = await api.post('/api/games', { name: name.trim(), savePath: path });
-      toast(`Now tracking "${game.name ?? name}"`, 'success');
+      toast($t('common.nowTracking', { name: game.name ?? name }), 'success');
       dispatch('close');
       navigate('game', { gameId: game.id });
     } catch (e) {
@@ -76,39 +77,39 @@
   }
 </script>
 
-<Modal title="Track a game" icon={FolderPlus} width={560} height="auto" onClose={() => dispatch('close')}>
+<Modal title={$t('home.addGame.title')} icon={FolderPlus} width={560} height="auto" onClose={() => dispatch('close')}>
   <div class="body">
     <div class="field">
-      <span class="label">Save folder or file</span>
+      <span class="label">{$t('home.addGame.savePath')}</span>
       {#if canPick}
         <div class="picked" title={path}><bdi>{path}</bdi></div>
         <div class="alt">
-          <button class="linklike" on:click={pickFolder}>Change folder…</button>
-          <button class="linklike" on:click={pickFile}>Track a single file instead…</button>
+          <button class="linklike" on:click={pickFolder}>{$t('home.addGame.changeFolder')}</button>
+          <button class="linklike" on:click={pickFile}>{$t('home.addGame.trackFileInstead')}</button>
         </div>
       {:else}
         <input id="g-path" placeholder="C:\Users\you\AppData\…" bind:value={path} />
       {/if}
     </div>
     <div class="field">
-      <label for="g-name">Name</label>
+      <label for="g-name">{$t('home.addGame.name')}</label>
       <input
         id="g-name"
         bind:this={nameInput}
-        placeholder="e.g. Elden Ring"
+        placeholder={$t('home.addGame.namePlaceholder')}
         bind:value={name}
         on:input={() => (typed = true)}
         on:keydown={(e) => e.key === 'Enter' && add()}
       />
-      <span class="hint">How it shows in your library, and on your other devices.</span>
+      <span class="hint">{$t('home.addGame.nameHint')}</span>
     </div>
   </div>
   <ModalFoot>
     <span />
     <div class="actions">
-      <button class="btn" on:click={() => dispatch('close')}>Cancel</button>
+      <button class="btn" on:click={() => dispatch('close')}>{$t('common.cancel')}</button>
       <button class="btn primary" disabled={!name.trim() || !path || adding} on:click={add}>
-        {adding ? 'Adding…' : 'Start tracking'}
+        {adding ? $t('home.addGame.adding') : $t('home.addGame.startTracking')}
       </button>
     </div>
   </ModalFoot>
diff --git a/cmd/opensave-app/frontend/src/views/home/HomeSummary.svelte b/cmd/opensave-app/frontend/src/views/home/HomeSummary.svelte
index 5e68ce4f..b2713df2 100644
--- a/cmd/opensave-app/frontend/src/views/home/HomeSummary.svelte
+++ b/cmd/opensave-app/frontend/src/views/home/HomeSummary.svelte
@@ -24,6 +24,7 @@
   import { api } from '../../lib/api.js';
   import { timeAgo } from '../../lib/timeago.js';
   import { libraryView } from '../../lib/libraryview.js';
+  import { t } from '../../lib/i18n.js';
   import RecentActivity from './RecentActivity.svelte';
 
   /** [{game, status}] for every tracked game, from the library. */
@@ -71,19 +72,19 @@
   $: online = paired.filter((p) => p.status === 'online');
   $: devices =
     paired.length === 0
-      ? 'None paired'
+      ? $t('home.summary.nonePaired')
       : paired.length === 1
-        ? `${paired[0].name} · ${online.length ? 'online' : 'offline'}`
-        : `${online.length} of ${paired.length} online`;
+        ? `${paired[0].name} · ${online.length ? $t('home.summary.online') : $t('home.summary.offline')}`
+        : $t('home.summary.devicesOnline', { online: online.length, paired: paired.length });
 
   // Set up, not just switched on: a fresh install has backup on with no
   // folder chosen, which backs up nothing.
   $: cloudOn = !!$settings?.cloudSync?.ready;
   $: cloud = cloudOn
-    ? (providerById($settings.cloudSync.provider)?.label ?? 'On')
+    ? (providerById($settings.cloudSync.provider)?.label ?? $t('home.summary.cloudOn'))
     : $settings?.cloudSync?.enabled
-      ? 'Not set up'
-      : 'Off';
+      ? $t('home.summary.cloudNotSetUp')
+      : $t('home.summary.cloudOff');
 
   $: space = spaceUsed(Object.fromEntries(rows.map((r) => [r.game.id, r.game])));
 
@@ -100,41 +101,41 @@
       <p class="headline" role="status">{summary.headline}</p>
       {#if lowSpace !== null}
         <p class="detail warn">
-          Only {fmtSize(lowSpace)} free on the drive your snapshots are kept on — new ones may not fit.
-          <button class="inline-link" on:click={() => navigate('settings', { tab: 'storage' })}>See what takes the space</button>
+          {$t('home.summary.lowSpace', { size: fmtSize(lowSpace) })}
+          <button class="inline-link" on:click={() => navigate('settings', { tab: 'storage' })}>{$t('home.summary.seeSpace')}</button>
         </p>
       {/if}
       {#if paused}
-        <p class="detail">
-          Syncing is paused {pauseLength($syncPause, now)}. Snapshots are still taken, and everything catches up when it
-          resumes.
-        </p>
+        <p class="detail">{$t('home.summary.pausedDetail', { length: pauseLength($syncPause, now) })}</p>
       {/if}
     </div>
     {#if paused}
-      <button class="btn small" on:click={resumeSync}>Resume now</button>
+      <button class="btn small" on:click={resumeSync}>{$t('home.summary.resumeNow')}</button>
     {/if}
   </div>
 
   <div class="facts">
-    <button class="fact link" on:click={() => navigate('devices')} title="Open Devices">
-      <span class="label">Devices</span>
+    <button class="fact link" on:click={() => navigate('devices')} title={$t('home.summary.devicesTitle')}>
+      <span class="label">{$t('home.devices')}</span>
       <span class="value" class:quiet={paired.length === 0}><span class="v">{devices}</span><ChevronRight size={13} class="go" /></span>
     </button>
-    <button class="fact link" on:click={() => navigate('cloud')} title="Open Cloud Backup">
-      <span class="label">Cloud backup</span>
+    <button class="fact link" on:click={() => navigate('cloud')} title={$t('home.summary.cloudBackupTitle')}>
+      <span class="label">{$t('home.summary.cloudBackup')}</span>
       <span class="value" class:quiet={!cloudOn}><span class="v">{cloud}</span><ChevronRight size={13} class="go" /></span>
     </button>
-    <div class="fact" title={newest ? `${newest.name} · ${new Date(newest.at).toLocaleString()}` : ''}>
-      <span class="label">Last snapshot</span>
-      <span class="value" class:quiet={!newest}><span class="v">{newest ? timeAgo(newest.at, now) : 'None yet'}</span></span>
+    <div
+      class="fact"
+      title={newest ? $t('home.summary.lastSnapshotTitle', { name: newest.name, when: new Date(newest.at).toLocaleString() }) : ''}
+    >
+      <span class="label">{$t('home.summary.lastSnapshot')}</span>
+      <span class="value" class:quiet={!newest}><span class="v">{newest ? timeAgo(newest.at, now) : $t('home.summary.noneYet')}</span></span>
     </div>
     <button
       class="fact link"
       on:click={() => navigate('settings', { tab: 'storage' })}
-      title={sharedSaving > 0 ? `On disk — ${fmtSize(sharedSaving)} less than the snapshots' own sizes, for sharing unchanged files. Open Settings → Storage` : 'Open Settings → Storage'}
+      title={sharedSaving > 0 ? $t('home.summary.sharedSavingTitle', { size: fmtSize(sharedSaving) }) : $t('home.summary.spaceUsedTitle')}
     >
-      <span class="label">Space used</span>
+      <span class="label">{$t('home.summary.spaceUsed')}</span>
       <span class="value"><span class="v">{fmtSize(Math.max(0, space - sharedSaving))}</span><ChevronRight size={13} class="go" /></span>
     </button>
   </div>
diff --git a/cmd/opensave-app/frontend/src/views/home/LibraryGrid.svelte b/cmd/opensave-app/frontend/src/views/home/LibraryGrid.svelte
index e122cd85..66c79d5c 100644
--- a/cmd/opensave-app/frontend/src/views/home/LibraryGrid.svelte
+++ b/cmd/opensave-app/frontend/src/views/home/LibraryGrid.svelte
@@ -12,6 +12,7 @@
   // once (e.g. clear a batch of wrongly-tracked entries) without going in and
   // out of each one.
   import { navigate, toast } from '../../lib/stores.js';
+  import { t } from '../../lib/i18n.js';
   import { api } from '../../lib/api.js';
   import Camera from 'lucide-svelte/icons/camera';
   import RefreshCw from 'lucide-svelte/icons/refresh-cw';
@@ -146,13 +147,14 @@
     }
     bulkBusy = false;
     const done = games.length - failed.length;
-    if (failed.length) toast(`${verb} ${done} of ${games.length} — ${failed.join('; ')}`, 'error');
-    else toast(`${verb} ${done} ${done === 1 ? 'game' : 'games'}`, 'success');
+    if (failed.length) toast($t('home.library.bulkPartial', { verb, done, total: games.length, failed: failed.join('; ') }), 'error');
+    else toast($t('home.library.bulkDone', { verb, n: done }), 'success');
   }
-  const snapshotPicked = () => forEachPicked('Took a snapshot of', (g) => api.post(`/api/games/${g.id}/snapshot`, { comment: '' }));
-  const syncPicked = () => forEachPicked('Started syncing', (g) => api.post(`/api/games/${g.id}/sync`, {}));
+  const snapshotPicked = () =>
+    forEachPicked($t('home.library.verbSnapshot'), (g) => api.post(`/api/games/${g.id}/snapshot`, { comment: '' }));
+  const syncPicked = () => forEachPicked($t('home.library.verbSync'), (g) => api.post(`/api/games/${g.id}/sync`, {}));
   const favouritePicked = () =>
-    forEachPicked('Added to Favourites:', (g) => api.post('/api/collections/favourites/games', { gameId: g.id, in: true }));
+    forEachPicked($t('home.library.verbFavourite'), (g) => api.post('/api/collections/favourites/games', { gameId: g.id, in: true }));
   // "All" is what is on screen: selecting games a filter is hiding, to then
   // untrack them, would act on things nobody was looking at.
   $: allSelected = shown.length > 0 && shown.every((r) => libSelected.has(r.game.id));
@@ -176,30 +178,52 @@
 />
 
 <div class="toolbar">
-  <h3>Library</h3>
-  <input class="search" type="search" data-find placeholder="Find a game…" bind:value={query} aria-label="Find a game" />
+  <h3>{$t('home.library.title')}</h3>
+  <input
+    class="search"
+    type="search"
+    data-find
+    placeholder={$t('home.library.searchPlaceholder')}
+    bind:value={query}
+    aria-label={$t('home.library.searchLabel')}
+  />
   <div class="spacer"></div>
   {#if selectMode}
-    <span class="select-count">{libSelected.size} selected</span>
+    <span class="select-count">{$t('home.library.selectedCount', { n: libSelected.size })}</span>
     <button class="btn small" on:click={toggleSelectAll}>
-      {allSelected ? 'Unselect all' : `Select all (${shown.length})`}
+      {allSelected ? $t('home.library.unselectAll') : $t('home.library.selectAll', { count: shown.length })}
     </button>
-    <button class="btn small" disabled={libSelected.size === 0 || bulkBusy} on:click={snapshotPicked} title="Take a snapshot of each">
-      <Camera size={14} />Snapshot
+    <button
+      class="btn small"
+      disabled={libSelected.size === 0 || bulkBusy}
+      on:click={snapshotPicked}
+      title={$t('home.library.snapshotTitle')}
+    >
+      <Camera size={14} />{$t('home.library.snapshot')}
     </button>
-    <button class="btn small" disabled={libSelected.size === 0 || bulkBusy} on:click={syncPicked} title="Sync each with your devices">
-      <RefreshCw size={14} />Sync
+    <button
+      class="btn small"
+      disabled={libSelected.size === 0 || bulkBusy}
+      on:click={syncPicked}
+      title={$t('home.library.syncTitle')}
+    >
+      <RefreshCw size={14} />{$t('home.library.sync')}
     </button>
-    <button class="btn small" disabled={libSelected.size === 0 || bulkBusy} on:click={favouritePicked} title="Add each to Favourites">
-      <Star size={14} />Favourite
+    <button
+      class="btn small"
+      disabled={libSelected.size === 0 || bulkBusy}
+      on:click={favouritePicked}
+      title={$t('home.library.favouriteTitle')}
+    >
+      <Star size={14} />{$t('home.library.favourite')}
     </button>
     <button class="btn small danger" disabled={libSelected.size === 0} on:click={untrackSelected}>
-      Untrack selected
+      {$t('home.library.untrackSelected')}
     </button>
-    <button class="btn small" on:click={stopSelecting}>Cancel</button>
+    <button class="btn small" on:click={stopSelecting}>{$t('common.cancel')}</button>
   {:else}
     <label class="sort">
-      <span>Sort</span>
+      <span>{$t('home.library.sort')}</span>
       <select bind:value={$libraryView.sort}>
         {#each Object.entries(SORTS) as [id, s]}
           <option value={id}>{s.label}</option>
@@ -209,25 +233,25 @@
     <button
       class="btn small icon order"
       on:click={() => libraryView.update((v) => ({ ...v, reverse: !v.reverse }))}
-      title={$libraryView.reverse ? 'Reversed — put back in order' : 'Reverse the order'}
-      aria-label="Reverse the order"
+      title={$libraryView.reverse ? $t('home.library.reversedTitle') : $t('home.library.reverseTitle')}
+      aria-label={$t('home.library.reverseTitle')}
       aria-pressed={$libraryView.reverse}
     >
       <svelte:component this={$libraryView.reverse ? ArrowUpNarrowWide : ArrowDownWideNarrow} size={15} />
     </button>
     <div class="view-anchor">
       <button class="btn small" class:active={viewOpen} aria-expanded={viewOpen} on:click={() => (viewOpen = !viewOpen)}>
-        <LayoutGrid size={14} />View
+        <LayoutGrid size={14} />{$t('home.library.view')}
       </button>
       {#if viewOpen}
         <div class="view-backdrop" use:backdropClose={() => (viewOpen = false)} role="presentation"></div>
-        <div class="view-panel card" role="dialog" aria-label="Library view">
+        <div class="view-panel card" role="dialog" aria-label={$t('home.library.viewLabel')}>
           <LibraryViewOptions />
-          <p class="view-hint">Also in Settings → General.</p>
+          <p class="view-hint">{$t('home.library.viewHint')}</p>
         </div>
       {/if}
     </div>
-    <button class="btn small" on:click={toggleSelectMode}><SquareCheckBig size={14} />Select</button>
+    <button class="btn small" on:click={toggleSelectMode}><SquareCheckBig size={14} />{$t('home.library.select')}</button>
   {/if}
 </div>
 
@@ -238,7 +262,7 @@
     {/if}
     {#if chips.length}
       {#if filters.length > 1}<span class="chip-sep" aria-hidden="true"></span>{/if}
-      <div class="collection-chips" role="group" aria-label="Collections">
+      <div class="collection-chips" role="group" aria-label={$t('home.library.collectionsLabel')}>
         {#each chips as c}
           <button class="collection-chip" class:active={$collectionFilter === c.id} aria-pressed={$collectionFilter === c.id} on:click={() => toggleCollection(c.id)}>
             {#if c.builtin}<Star size={12} />{/if}{c.label}<span class="count">{c.count}</span>
@@ -251,8 +275,12 @@
 
 {#if shown.length === 0}
   <div class="none">
-    <p>No games match{query.trim() ? ` "${query.trim()}"` : ''}.</p>
-    <button class="btn small" on:click={clearFilters}>Clear filters</button>
+    {#if query.trim()}
+      <p>{$t('home.library.emptyFor', { query: query.trim() })}</p>
+    {:else}
+      <p>{$t('home.library.empty')}</p>
+    {/if}
+    <button class="btn small" on:click={clearFilters}>{$t('home.library.clearFilters')}</button>
   </div>
 {:else}
   <div class="grid" style="grid-template-columns: {gridColumns($libraryView)}" on:keydown={gridKeys} role="presentation">
@@ -270,7 +298,10 @@
     {/each}
   </div>
   {#if filtering}
-    <p class="showing">Showing {shown.length} of {rows.length}. <button class="linklike" on:click={clearFilters}>Show all</button></p>
+    <p class="showing">
+      {$t('home.library.showing', { shown: shown.length, total: rows.length })}
+      <button class="linklike" on:click={clearFilters}>{$t('home.library.showAll')}</button>
+    </p>
   {/if}
 {/if}
 
diff --git a/cmd/opensave-app/frontend/src/views/home/LibraryTile.svelte b/cmd/opensave-app/frontend/src/views/home/LibraryTile.svelte
index 744ad92e..443a36bb 100644
--- a/cmd/opensave-app/frontend/src/views/home/LibraryTile.svelte
+++ b/cmd/opensave-app/frontend/src/views/home/LibraryTile.svelte
@@ -6,6 +6,7 @@
   // someone found. Art whose shape is far from the tile's is shown whole over
   // a blurred copy of itself rather than cropped to a sliver of its middle.
   import { createEventDispatcher, onDestroy } from 'svelte';
+  import { t, segments } from '../../lib/i18n.js';
   import Check from 'lucide-svelte/icons/check';
   import CoverImage from '../../components/CoverImage.svelte';
   import { gameCover, isDaemonURL } from '../../lib/api.js';
@@ -166,7 +167,7 @@
   </div>
   <div class="body">
     <div class="name">
-      {#if isFavourite($collections, game.id)}<span class="fav" title="In Favourites"><Star size={12} /></span>{/if}{game.name}
+      {#if isFavourite($collections, game.id)}<span class="fav" title={$t('home.tile.inFavourites')}><Star size={12} /></span>{/if}{game.name}
     </div>
     <div class="status tone-{status.tone}">
       {#if status.tone === 'warn'}<TriangleAlert size={13} class="status-icon" />{:else if status.tone === 'playing'}<Gamepad2
@@ -179,9 +180,9 @@
     </div>
     {#if cover === 'wide'}
       <div class="meta">
-        {snapshots} {snapshots === 1 ? 'snapshot' : 'snapshots'}{#if game.playtimeMs >= 60_000}{' · '}{playLength(game.playtimeMs)} played{/if}
+        {$t('home.tile.snapshots', { n: snapshots })}{#if game.playtimeMs >= 60_000}{' · '}{$t('home.tile.played', { length: playLength(game.playtimeMs) })}{/if}
         {#if game.activeBranch && game.activeBranch !== 'main'}
-          · on <strong>{game.activeBranch}</strong>
+          {' · '}{#each segments($t('home.tile.onBranch', { branch: game.activeBranch }), { branch: game.activeBranch }, ['branch']) as part}{#if part.bold}<strong>{part.text}</strong>{:else}{part.text}{/if}{/each}
         {/if}
       </div>
     {/if}
diff --git a/cmd/opensave-app/frontend/src/views/home/LibraryViewOptions.svelte b/cmd/opensave-app/frontend/src/views/home/LibraryViewOptions.svelte
index 2af5260a..8a438c0e 100644
--- a/cmd/opensave-app/frontend/src/views/home/LibraryViewOptions.svelte
+++ b/cmd/opensave-app/frontend/src/views/home/LibraryViewOptions.svelte
@@ -2,6 +2,7 @@
   // How the library looks: cover style, tiles per row, tile size. Shown in
   // Settings and in the library's View menu; both change the same thing, at
   // once. See lib/libraryview.js.
+  import { t } from '../../lib/i18n.js';
   import { slidingIndicator } from '../../lib/motion.js';
   import { libraryView, COVER_STYLES, TILE_SIZES, COLUMN_CHOICES } from '../../lib/libraryview.js';
 
@@ -10,8 +11,8 @@
 
 <div class="options">
   <div class="group">
-    <div class="label">Covers</div>
-    <div class="styles" role="radiogroup" aria-label="Cover style">
+    <div class="label">{$t('home.viewOptions.covers')}</div>
+    <div class="styles" role="radiogroup" aria-label={$t('home.viewOptions.coverStyle')}>
       {#each Object.entries(COVER_STYLES) as [id, style]}
         <button
           class="style"
@@ -31,16 +32,16 @@
 
   <div class="row">
     <label class="group">
-      <span class="label">Tiles per row</span>
+      <span class="label">{$t('home.viewOptions.tilesPerRow')}</span>
       <select value={String($libraryView.columns)} on:change={(e) => set({ columns: e.currentTarget.value === 'auto' ? 'auto' : Number(e.currentTarget.value) })}>
         {#each COLUMN_CHOICES as c}
-          <option value={String(c)}>{c === 'auto' ? 'As many as fit' : c}</option>
+          <option value={String(c)}>{c === 'auto' ? $t('home.viewOptions.autoFit') : c}</option>
         {/each}
       </select>
     </label>
 
     <div class="group">
-      <span class="label">Tile size</span>
+      <span class="label">{$t('home.viewOptions.tileSize')}</span>
       <div class="segmented" class:off={$libraryView.columns !== 'auto'} use:slidingIndicator={{ mode: 'fill' }}>
         {#each Object.entries(TILE_SIZES) as [id, label]}
           <button
@@ -55,12 +56,12 @@
     </div>
   </div>
   {#if $libraryView.columns !== 'auto'}
-    <p class="note">With a set number per row, the tiles share the width between them.</p>
+    <p class="note">{$t('home.viewOptions.fixedNote')}</p>
   {/if}
 
   <label class="check">
     <input type="checkbox" checked={$libraryView.overview} on:change={(e) => set({ overview: e.currentTarget.checked })} />
-    Show recent activity on Home
+    {$t('home.viewOptions.overview')}
   </label>
 </div>
 
diff --git a/cmd/opensave-app/frontend/src/views/home/OfferedGames.svelte b/cmd/opensave-app/frontend/src/views/home/OfferedGames.svelte
index a69986ec..d039a1cb 100644
--- a/cmd/opensave-app/frontend/src/views/home/OfferedGames.svelte
+++ b/cmd/opensave-app/frontend/src/views/home/OfferedGames.svelte
@@ -9,6 +9,7 @@
   import { gameList, toast } from '../../lib/stores.js';
   import { withUndo, hiddenKeys } from '../../lib/undo.js';
   import { api, native } from '../../lib/api.js';
+  import { t, segments } from '../../lib/i18n.js';
 
   let offeredGames = [];
   async function load() {
@@ -24,11 +25,11 @@
   $: if ($gameList) load();
 
   async function place(offer) {
-    const dir = await native.selectDirectory(`Folder for "${offer.name}" on this device`);
+    const dir = await native.selectDirectory($t('home.offered.folderPrompt', { name: offer.name }));
     if (!dir) return;
     try {
       await api.post(`/api/offered-games/${offer.gameId}/place`, { path: dir });
-      toast(`${offer.name} is now tracked here`, 'success');
+      toast($t('home.offered.trackedToast', { name: offer.name }), 'success');
       await load();
     } catch (e) {
       toast(e.message, 'error');
@@ -37,7 +38,7 @@
 
   function decline(offer) {
     withUndo({
-      message: `You won't be asked about ${offer.name} again. Tracking it yourself later still works.`,
+      message: $t('home.offered.declineToast', { name: offer.name }),
       keys: [`offer:${offer.gameId}`],
       stillThere: () => offeredGames.some((o) => o.gameId === offer.gameId),
       run: async () => {
@@ -51,23 +52,21 @@
 
 {#if shownOffers.length > 0}
   <div class="card offers">
-    <h3>Waiting for a folder</h3>
-    <p class="intro">
-      {shownOffers.length === 1 ? 'Another device syncs this game' : 'Other devices sync these games'},
-      but this one doesn't know where to keep
-      {shownOffers.length === 1 ? 'it' : 'them'} yet. Nothing syncs until you choose.
-    </p>
+    <h3>{$t('home.offered.title')}</h3>
+    <p class="intro">{$t('home.offered.intro', { n: shownOffers.length })}</p>
     {#each shownOffers as offer (offer.gameId + offer.peerId)}
       <div class="row">
         <div class="info">
           <strong>{offer.name}</strong>
-          <span class="hint">
-            Kept at <code>{offer.peerPath}</code> on the other device.
-          </span>
+          <span class="hint"
+            >{#each segments($t('home.offered.pathHint'), { path: offer.peerPath }, ['path']) as part}{#if part.bold}<code
+                >{part.text}</code
+              >{:else}{part.text}{/if}{/each}</span
+          >
         </div>
         <div class="actions">
-          <button class="btn primary" on:click={() => place(offer)}>Choose folder…</button>
-          <button class="btn" on:click={() => decline(offer)}>Decline</button>
+          <button class="btn primary" on:click={() => place(offer)}>{$t('home.offered.chooseFolder')}</button>
+          <button class="btn" on:click={() => decline(offer)}>{$t('home.offered.decline')}</button>
         </div>
       </div>
     {/each}
diff --git a/cmd/opensave-app/frontend/src/views/home/RecentActivity.svelte b/cmd/opensave-app/frontend/src/views/home/RecentActivity.svelte
index faf9af7c..828316a4 100644
--- a/cmd/opensave-app/frontend/src/views/home/RecentActivity.svelte
+++ b/cmd/opensave-app/frontend/src/views/home/RecentActivity.svelte
@@ -19,6 +19,7 @@
   import { gameCover } from '../../lib/api.js';
   import { recentEvents } from '../../lib/overview.js';
   import { timeAgo } from '../../lib/timeago.js';
+  import { t } from '../../lib/i18n.js';
 
   const MOST = 6;
   const MIN_WIDTH = 210;
@@ -43,12 +44,12 @@
 
 <div class="recent">
   <div class="head">
-    <span class="label">Recent</span>
-    <button class="more" on:click={() => navigate('activity')}>All activity<ArrowRight size={12} /></button>
+    <span class="label">{$t('home.recent.label')}</span>
+    <button class="more" on:click={() => navigate('activity')}>{$t('home.recent.allActivity')}<ArrowRight size={12} /></button>
   </div>
   <div class="row" bind:clientWidth={width} style="grid-template-columns: repeat({fit}, minmax(0, 1fr))">
     {#if events.length === 0}
-      <p class="empty">Nothing yet. Snapshots and syncs show up here as they happen.</p>
+      <p class="empty">{$t('home.recent.empty')}</p>
     {:else}
       {#each shown as e (`${e.game.id}:${e.kind}:${e.at}`)}
         <button class="item" on:click={() => navigate('game', { gameId: e.game.id })} title={new Date(e.at).toLocaleString()}>
diff --git a/cmd/opensave-app/frontend/src/views/home/ScanDialog.svelte b/cmd/opensave-app/frontend/src/views/home/ScanDialog.svelte
index 872d960d..174ed33e 100644
--- a/cmd/opensave-app/frontend/src/views/home/ScanDialog.svelte
+++ b/cmd/opensave-app/frontend/src/views/home/ScanDialog.svelte
@@ -8,6 +8,7 @@
   import { api, coverURL } from '../../lib/api.js';
   import Modal from '../../components/ui/Modal.svelte';
   import { withUndo, hiddenKeys } from '../../lib/undo.js';
+  import { t } from '../../lib/i18n.js';
   import Chevron from '../../components/ui/Chevron.svelte';
   import ScanSearch from 'lucide-svelte/icons/scan-search';
   import Gamepad2 from 'lucide-svelte/icons/gamepad-2';
@@ -60,7 +61,7 @@
       const results = (await api.get('/api/presets/scan')) ?? [];
       // A list, always. Anything else is not a scan, and reading one as a
       // list failed with "i is not iterable" — which says nothing.
-      if (!Array.isArray(results)) throw new Error("The scan's answer was not a list of saves. Restart OpenSave and scan again.");
+      if (!Array.isArray(results)) throw new Error($t('home.scan.badResponse'));
       fillMissingAppIds(results);
       scanResults = results;
     } catch (e) {
@@ -89,7 +90,7 @@
     selected.delete(item.id);
     selected = selected;
     withUndo({
-      message: `"${item.name}" won't be offered in scans again.`,
+      message: $t('home.scan.excludeToast', { name: item.name }),
       keys: [`scan:${item.savePath}`],
       stillThere: () => (scanResults ?? []).some((r) => r.id === item.id),
       run: async () => {
@@ -228,11 +229,11 @@
       const { failed } = await trackAsOneGame(primary, extras);
       consumeRows(new Set(group.suggested.map((m) => m.id)));
       if (failed.length > 0) {
-        toast(`Tracking "${primary.name}" — ${failed.length} folder(s) could not be added: ${failed[0]}`, 'error');
+        toast($t('home.scan.trackPartialFail', { name: primary.name, n: failed.length, detail: failed[0] }), 'error');
       } else if (extras.length > 0) {
-        toast(`Now tracking "${primary.name}" across ${extras.length + 1} folders`, 'success');
+        toast($t('home.scan.trackedAcrossFolders', { name: primary.name, n: extras.length + 1 }), 'success');
       } else {
-        toast(`Now tracking "${primary.name}"`, 'success');
+        toast($t('common.nowTracking', { name: primary.name }), 'success');
       }
     } catch (e) {
       toast(e.message, 'error');
@@ -263,8 +264,10 @@
 
     consumeRows(new Set(items.map((i) => i.id)));
     clearSelection();
-    const extra = locations > 0 ? ` with ${locations} extra location${locations === 1 ? '' : 's'}` : '';
-    toast(`Tracked ${games} game${games === 1 ? '' : 's'}${extra}`, problems.length > 0 ? 'error' : 'success');
+    toast(
+      locations > 0 ? $t('home.scan.trackedGamesWithExtras', { n: games, m: locations }) : $t('home.scan.trackedGames', { n: games }),
+      problems.length > 0 ? 'error' : 'success'
+    );
     if (problems.length > 0) toast(problems[0], 'error');
     if (filteredResults.length === 0) close();
   }
@@ -284,41 +287,46 @@
       const { failed } = await trackAsOneGame(primary, extras);
       consumeRows(new Set(items.map((i) => i.id)));
       clearSelection();
-      if (failed.length > 0) toast(`Tracked "${primary.name}", but ${failed.length} folder(s) failed: ${failed[0]}`, 'error');
-      else toast(`Tracking "${primary.name}" across ${items.length} folders`, 'success');
+      if (failed.length > 0) toast($t('home.scan.mergedPartialFail', { name: primary.name, n: failed.length, detail: failed[0] }), 'error');
+      else toast($t('home.scan.trackedAcrossFolders', { name: primary.name, n: items.length }), 'success');
       if (filteredResults.length === 0) close();
     } catch (e) {
       toast(e.message, 'error');
     }
   }
 
-  const typeLabels = { emulator: 'Emulator', repack: 'Repack', game: 'Game' };
+  $: typeLabels = { emulator: $t('home.scan.type.emulator'), repack: $t('home.scan.type.repack'), game: $t('home.scan.type.game') };
   const typeIcon = (t) => (t === 'emulator' ? Joystick : t === 'repack' ? Package : Gamepad2);
-  const typeTabs = [['all', 'All'], ['game', 'Games'], ['emulator', 'Emulators'], ['repack', 'Repacks']];
+  $: typeTabs = [
+    ['all', $t('home.scan.tab.all')],
+    ['game', $t('home.scan.tab.games')],
+    ['emulator', $t('home.scan.tab.emulators')],
+    ['repack', $t('home.scan.tab.repacks')]
+  ];
 </script>
 
 <svelte:window on:keydown={onKeydown} />
 
 {#if open}
-  <Modal title="Scan results" icon={ScanSearch} onClose={close} width={920} height="min(82vh, 860px)">
+  <Modal title={$t('home.scan.title')} icon={ScanSearch} onClose={close} width={920} height="min(82vh, 860px)">
     <svelte:fragment slot="sub">
-      {#if scanning}Scanning your system…{:else}Found {scanCounts.all} save location{scanCounts.all === 1 ? '' : 's'} — {availableGroups.length} available to track{#if emptyCount > 0 && !showEmpty}, {emptyCount} empty hidden{/if}{/if}
+      {#if scanning}{$t('home.scan.subScanning')}{:else if emptyCount > 0 && !showEmpty}{$t('home.scan.foundSummaryEmpty', { n: scanCounts.all, m: availableGroups.length, e: emptyCount })}{:else}{$t('home.scan.foundSummary', { n: scanCounts.all, m: availableGroups.length })}{/if}
     </svelte:fragment>
 
     {#if scanning}
-      <ModalLoading>Scanning Steam, emulators, and configured folders…</ModalLoading>
+      <ModalLoading>{$t('home.scan.scanningDetail')}</ModalLoading>
     {:else}
       <div class="toolbar">
-        <SearchInput placeholder="Filter by name or path…" bind:value={scanFilter} />
+        <SearchInput placeholder={$t('home.scan.filterPlaceholder')} bind:value={scanFilter} />
         <FilterTabs options={typeTabs} counts={scanCounts} bind:value={scanType} />
-        <label class="toggle" title="Also show saves you already track">
+        <label class="toggle" title={$t('home.scan.showTrackedTitle')}>
           <input type="checkbox" bind:checked={showTracked} />
-          Show tracked
+          {$t('home.scan.showTracked')}
         </label>
         {#if emptyCount > 0}
-          <label class="toggle" title="Folders that exist but hold no files — Steam makes one for every game you own, whether or not saves go there. A game with nothing saved anywhere is in here too.">
+          <label class="toggle" title={$t('home.scan.showEmptyTitle')}>
             <input type="checkbox" bind:checked={showEmpty} />
-            Show {emptyCount} empty
+            {$t('home.scan.showEmpty', { n: emptyCount })}
           </label>
         {/if}
       </div>
@@ -330,7 +338,7 @@
             {@const tracked = isTracked(item)}
             {#if i === availableGroups.length && trackedGroups.length > 0}
               <div class="divider">
-                Already tracked ({trackedGroups.length})
+                {$t('home.scan.alreadyTracked', { n: trackedGroups.length })}
               </div>
             {/if}
             <!--
@@ -347,7 +355,7 @@
               icon={typeIcon(item.type)}
               selected={groupSelected(group, selected)}
               badge={typeLabels[item.type] ?? item.type}
-              stamp={tracked ? 'Tracked' : ''}
+              stamp={tracked ? $t('home.scan.tracked') : ''}
               dimmed={tracked}
               faded={isEmptyResult(item)}
               meta={contentsLabel(item)}
@@ -356,15 +364,15 @@
             >
               <svelte:fragment slot="hover">
                 <button class="btn small primary" on:click|stopPropagation={() => trackGroup(group)}>
-                  {group.suggested.length > 1 ? `Track all ${group.suggested.length}` : 'Track'}
+                  {group.suggested.length > 1 ? $t('home.scan.trackAll', { n: group.suggested.length }) : $t('home.scan.track')}
                 </button>
                 <button
                   class="btn small"
                   disabled={excluding === item.id}
-                  title="Stop offering this location in future scans"
+                  title={$t('home.scan.excludeTitle')}
                   on:click|stopPropagation={() => excludeResult(item)}
                 >
-                  {excluding === item.id ? 'Excluding…' : 'Exclude'}
+                  {excluding === item.id ? $t('home.scan.excluding') : $t('home.scan.exclude')}
                 </button>
               </svelte:fragment>
               {#if group.extras.length > 0}
@@ -373,8 +381,8 @@
                   class:open={expandedGroup === group.id}
                   on:click|stopPropagation={() => (expandedGroup = expandedGroup === group.id ? null : group.id)}
                 >
-                  <Chevron open={expandedGroup === group.id} size={12} /> found in {group.members.length} folders
-                  {#if group.suggested.length > 1}<span class="folders-hint">· {group.suggested.length} are one save</span>{/if}
+                  <Chevron open={expandedGroup === group.id} size={12} /> {$t('home.scan.foundInFolders', { n: group.members.length })}
+                  {#if group.suggested.length > 1}<span class="folders-hint">{$t('home.scan.oneSave', { n: group.suggested.length })}</span>{/if}
                 </button>
               {/if}
             </CoverTile>
@@ -384,7 +392,7 @@
             {/if}
           {:else}
             <div class="empty-grid">
-              {scanCounts.all === 0 ? 'Nothing detected. You can still track any folder manually.' : 'No matches for this filter.'}
+              {scanCounts.all === 0 ? $t('home.scan.emptyNothingDetected') : $t('home.scan.emptyNoMatches')}
             </div>
           {/each}
         </div>
@@ -392,9 +400,9 @@
 
       <ModalFoot>
         <div class="actions">
-          <button class="btn small" on:click={selectAllVisible} disabled={availableGroups.length === 0}>Select all ({availableGroups.length})</button>
+          <button class="btn small" on:click={selectAllVisible} disabled={availableGroups.length === 0}>{$t('home.scan.selectAll', { n: availableGroups.length })}</button>
           {#if selectedCount > 0}
-            <button class="btn small" on:click={clearSelection}>Clear</button>
+            <button class="btn small" on:click={clearSelection}>{$t('home.scan.clear')}</button>
           {/if}
         </div>
         <!-- Both tracking actions sit together on the right: they are the
@@ -404,14 +412,14 @@
           {#if selectedCount > 1}
             <button
               class="btn primary"
-              title="Track everything ticked as a single game, whatever it was grouped under. For a split save the scan did not spot."
+              title={$t('home.scan.trackAsOneTitle')}
               on:click={mergeSelectedIntoOneGame}
             >
-              Track as one game
+              {$t('home.scan.trackAsOne')}
             </button>
           {/if}
           <button class="btn primary" disabled={selectedCount === 0} on:click={trackSelected}>
-            Track selected ({selectedCount})
+            {$t('home.scan.trackSelected', { n: selectedCount })}
           </button>
         </div>
       </ModalFoot>
diff --git a/cmd/opensave-app/frontend/src/views/home/ScanFolderList.svelte b/cmd/opensave-app/frontend/src/views/home/ScanFolderList.svelte
index ef1668ee..156ce9f3 100644
--- a/cmd/opensave-app/frontend/src/views/home/ScanFolderList.svelte
+++ b/cmd/opensave-app/frontend/src/views/home/ScanFolderList.svelte
@@ -3,6 +3,7 @@
   // Ticking one fires `toggle` with its id.
   import { createEventDispatcher } from 'svelte';
   import { contentsLabel, normPath } from '../../lib/scan.js';
+  import { t, segments } from '../../lib/i18n.js';
 
   export let group;
   export let selected = new Set();
@@ -14,8 +15,8 @@
 
 <div class="panel">
   <div class="head">
-    <strong>{group.primary.name}</strong> was found in {group.members.length} places.
-    Tick the folders that belong to this save — they are tracked as one game.
+    {#each segments($t('home.scan.folderList.headFound'), { name: group.primary.name, n: group.members.length }, ['name']) as part}{#if part.bold}<strong>{part.text}</strong>{:else}{part.text}{/if}{/each}
+    {$t('home.scan.folderList.headTick')}
   </div>
   {#each group.members as m (m.id)}
     {@const tracked = trackedPaths.has(normPath(m.savePath))}
@@ -30,11 +31,11 @@
         <span class="path">{m.savePath}</span>
         <span class="meta">
           {contentsLabel(m)}
-          {#if m.role === 'primary'}<span class="tag tag-primary">the save folder</span>
-          {:else if m.role === 'location'}<span class="tag tag-loc">part of the same save</span>
-          {:else if m.role === 'inside'}<span class="tag">already inside the folder above</span>
-          {:else if m.role === 'alternative'}<span class="tag tag-alt">another copy — probably an old install</span>{/if}
-          {#if tracked}<span class="tag tag-primary">already tracked</span>{/if}
+          {#if m.role === 'primary'}<span class="tag tag-primary">{$t('home.scan.folderList.tagSave')}</span>
+          {:else if m.role === 'location'}<span class="tag tag-loc">{$t('home.scan.folderList.tagLocation')}</span>
+          {:else if m.role === 'inside'}<span class="tag">{$t('home.scan.folderList.tagInside')}</span>
+          {:else if m.role === 'alternative'}<span class="tag tag-alt">{$t('home.scan.folderList.tagAlt')}</span>{/if}
+          {#if tracked}<span class="tag tag-primary">{$t('home.scan.folderList.tagTracked')}</span>{/if}
         </span>
       </span>
     </label>
diff --git a/cmd/opensave-app/frontend/src/views/home/SetupGuide.svelte b/cmd/opensave-app/frontend/src/views/home/SetupGuide.svelte
index 20d22800..51468333 100644
--- a/cmd/opensave-app/frontend/src/views/home/SetupGuide.svelte
+++ b/cmd/opensave-app/frontend/src/views/home/SetupGuide.svelte
@@ -10,6 +10,7 @@
   import X from 'lucide-svelte/icons/x';
   import { gameList, peers, settings, navigate } from '../../lib/stores.js';
   import { setupState, setupSteps } from '../../lib/setup.js';
+  import { t } from '../../lib/i18n.js';
 
   /** Whether a scan is running, from the page's scan dialog. */
   export let scanning = false;
@@ -25,21 +26,23 @@
   const skip = (id) => setupState.update((s) => ({ ...s, skipped: [...new Set([...s.skipped, id])] }));
   const later = () => setupState.update((s) => ({ ...s, dismissed: true }));
 
+  // Steps carry i18n keys rather than text: the copy has to follow the picked
+  // language, which means reading `t` at render time, not once here.
   const copy = {
     saves: {
       icon: ScanSearch,
-      title: 'Find your game saves',
-      text: 'OpenSave looks through Steam, emulators and the usual save folders, and you choose what to keep.'
+      titleKey: 'home.setup.stepSaves.title',
+      textKey: 'home.setup.stepSaves.text'
     },
     devices: {
       icon: MonitorSmartphone,
-      title: 'Add your other devices',
-      text: 'A PC, a Steam Deck or a handheld with OpenSave on it — on your Wi-Fi, or anywhere over the internet.'
+      titleKey: 'home.setup.stepDevices.title',
+      textKey: 'home.setup.stepDevices.text'
     },
     cloud: {
       icon: Cloud,
-      title: 'Back up to the cloud',
-      text: 'A copy of every snapshot in Google Drive, OneDrive, Dropbox or a folder of your own.'
+      titleKey: 'home.setup.stepCloud.title',
+      textKey: 'home.setup.stepCloud.text'
     }
   };
 </script>
@@ -47,10 +50,10 @@
 <div class="card guide">
   <div class="top">
     <div>
-      <h3>Get OpenSave set up</h3>
-      <p class="progress">{plan.settled} of 3 done</p>
+      <h3>{$t('home.setup.title')}</h3>
+      <p class="progress">{$t('home.setup.progress', { n: plan.settled })}</p>
     </div>
-    <button class="btn small ghost" on:click={later} title="Hide this guide"><X size={14} />Later</button>
+    <button class="btn small ghost" on:click={later} title={$t('home.setup.hideTitle')}><X size={14} />{$t('home.setup.later')}</button>
   </div>
   <ol>
     {#each plan.steps as step, i}
@@ -60,21 +63,21 @@
           {#if step.done}<Check size={14} strokeWidth={3} />{:else}{i + 1}{/if}
         </span>
         <div class="body">
-          <div class="title">{c.title}{#if step.skipped}<span class="tag">Skipped</span>{/if}</div>
+          <div class="title">{$t(c.titleKey)}{#if step.skipped}<span class="tag">{$t('home.setup.skipped')}</span>{/if}</div>
           {#if plan.next === step.id}
-            <p class="text">{c.text}</p>
+            <p class="text">{$t(c.textKey)}</p>
             <div class="actions">
               {#if step.id === 'saves'}
                 <button class="btn small primary" disabled={scanning} on:click={() => dispatch('scan')}>
-                  <ScanSearch size={14} />{scanning ? 'Scanning…' : 'Scan for saves'}
+                  <ScanSearch size={14} />{scanning ? $t('home.scanning') : $t('home.welcome.scanForSaves')}
                 </button>
-                <button class="btn small" on:click={() => dispatch('add')}><FolderPlus size={14} />Pick a folder</button>
+                <button class="btn small" on:click={() => dispatch('add')}><FolderPlus size={14} />{$t('home.setup.pickFolder')}</button>
               {:else if step.id === 'devices'}
-                <button class="btn small primary" on:click={() => navigate('devices')}><MonitorSmartphone size={14} />Pair a device</button>
-                <button class="btn small ghost" on:click={() => skip('devices')}>Only this device for now</button>
+                <button class="btn small primary" on:click={() => navigate('devices')}><MonitorSmartphone size={14} />{$t('home.setup.pairDevice')}</button>
+                <button class="btn small ghost" on:click={() => skip('devices')}>{$t('home.setup.onlyThisDevice')}</button>
               {:else}
-                <button class="btn small primary" on:click={() => navigate('cloud')}><Cloud size={14} />Choose where</button>
-                <button class="btn small ghost" on:click={() => skip('cloud')}>No cloud backup</button>
+                <button class="btn small primary" on:click={() => navigate('cloud')}><Cloud size={14} />{$t('home.setup.chooseWhere')}</button>
+                <button class="btn small ghost" on:click={() => skip('cloud')}>{$t('home.setup.noCloudBackup')}</button>
               {/if}
             </div>
           {/if}
diff --git a/cmd/opensave-app/frontend/src/views/settings/AppearanceOptions.svelte b/cmd/opensave-app/frontend/src/views/settings/AppearanceOptions.svelte
index 24a4bdbd..2d86b467 100644
--- a/cmd/opensave-app/frontend/src/views/settings/AppearanceOptions.svelte
+++ b/cmd/opensave-app/frontend/src/views/settings/AppearanceOptions.svelte
@@ -7,12 +7,23 @@
   import MonitorCog from 'lucide-svelte/icons/monitor-cog';
   import { appearance, THEMES, ACCENTS, SCALES, onAccent } from '../../lib/appearance.js';
   import { systemReducesMotion, slidingIndicator } from '../../lib/motion.js';
+  import { locale, LOCALES, t, SYSTEM_LOCALE } from '../../lib/i18n.js';
 
   const set = (patch) => appearance.update((v) => ({ ...v, ...patch }));
   const themeIcons = { dark: Moon, light: Sun, system: MonitorCog };
 </script>
 
 <div class="options">
+  <label class="group">
+    <span class="label">{$t('settings.language')}</span>
+    <select value={$locale} on:change={(e) => locale.set(e.currentTarget.value)}>
+      <option value={SYSTEM_LOCALE}>{$t('settings.systemDefault')}</option>
+      {#each Object.entries(LOCALES) as [id, label]}
+        <option value={id}>{label}</option>
+      {/each}
+    </select>
+  </label>
+
   <div class="group">
     <span class="label" id="ap-theme">Theme</span>
     <div class="segmented" role="radiogroup" aria-labelledby="ap-theme" use:slidingIndicator={{ mode: 'fill' }}>