OverBoard

Smartboard ink that sticks to the page.

OverBoard is a free writing layer for interactive whiteboards. Write on a worksheet with the board pen, scroll, and your ink scrolls with the page instead of floating on top of the screen. Wipe with your palm to erase. Highlight without covering the words. Save a PDF with the ink on it.

It runs in the browser. No accounts, no uploads; your ink stays on your machine.

Try the demo → · Write on a PDF or HTML worksheet →

Why this exists

The ink tool that ships with a lot of classroom smartboards draws on a see-through layer over the whole screen. It has no idea what's underneath, so when you scroll a worksheet, the ink stays put and ends up on top of the wrong question. OverBoard draws inside the page, so ink always stays where you wrote it.

Features

• Ink that scrolls with the page, and stays lined up when you zoom or resize the window
• Write in the margins: the blank space beside the page is writable too (it just doesn't print)
• Palm eraser on SMART Boards: wipe with your palm, fist or the side of your hand
• Finger scrolls, pen writes, with a toolbar switch if you lose the pen
• Highlighter that sits behind the printed text, so words stay readable
• Cover: tap the ▾ beside Highlighter and pick a cover to black out answers; wipe it away with your palm to reveal them. The same menu sets highlight strength (10–100%)
• Select: circle ink with the pen (or tap one mark), then send a copy to another class period, copy and paste it onto another page, drag it somewhere else, or delete it. A dashed blue box shows what's selected, with its menu beside it (a right-click on the box opens it too)
• Undo and Redo (↶ ↷ on the toolbar, or Ctrl/⌘+Z and Ctrl/⌘+Y, Ctrl/⌘+R or Ctrl/⌘+Shift+Z). Reloading from the keyboard is turned off, so a slip can't throw away the page
• 8 colors + a custom color picker, pen size and smoothing controls (hold − / + to repeat)
• Separate ink for each class period on the same worksheet: P1–P4 to start, or set your own in Settings & help ▸ Settings… (1–12 periods, any names)
• Settings & help ▸ Settings…: class periods (tap a style such as Block A, B… or A1… B1… for A/B days, or type your own names), the pen color at start, and Reset tools to defaults. Saved in the browser, so every worksheet and PDF on that computer uses them. The website and worksheets opened from your computer keep separate settings.
• 8 languages: English, Español, 中文 (Mandarin), Tagalog, Tiếng Việt, Français, Português (Brasil) and العربية (Arabic), in Settings & help ▸ Settings… ▸ 🌐 Language (or the 🌐 list on the PDF app's start screen). It changes OverBoard's buttons, tooltips and messages (and the Board not working? page), not your worksheet. OverBoard starts in the browser's own language when it has it. Translations by Claude; corrections from native speakers are very welcome (shared/strings.js).
• Tooltips: hold the mouse (or pen) over any button, or the smoothing squiggle, to see what it does.
• Save PDF with crisp ink, page by page
• Clear page / Clear all (Undo brings either back), and − / Fit / + zoom that keeps the toolbar the same size, on PDFs and HTML worksheets alike. On a small screen (a laptop) the toolbar shrinks to fit instead of scrolling
• PDFs too: worksheets or whole textbooks, with a chapter list, page jump, and Export PDF with your ink drawn in
• Start from a blank page: blank, lined, graph, dot or isometric paper, and add or remove pages as you go
• The PDF's text stays text: select and copy it, follow its links, and search the whole book (great with OCR'd scans). Exports keep it.
• Autosave in the browser, plus optional save ink into the .html file itself (Chrome/Edge)
• Hide the toolbar down to a small button when you want the whole screen
• ⏱ Timer: big buttons to set it (1–15 minutes, or − / + and hold to go faster), a big countdown you can drag aside or shrink, and a chime at zero (or your own .wav / .mp3 in Settings ▸ Timer sound)
• Colors follow the tool: pen colors for the pen, highlighter colors (yellow first) for the highlighter, cover colors for covers, plus the color picker
• Install the PDF app in Chrome or Edge: it opens from the Dock or Start menu and works with no internet

Use it on a PDF

Open bpmdata.github.io/OverBoard/app and drop in a PDF (or tap to choose one). The PDF opens in the browser; nothing is uploaded.

• Same toolbar as the HTML overlay: pen, highlighter, palm eraser, finger scrolls, colors, size, smoothing, class periods, undo and redo, Clear page / Clear all, zoom and Settings & help ▸.
• Cover answers: tap ▾ next to Highlighter and choose Cover (black, light gray, white, or any color with the color picker). It draws a solid bar over the page, text included; wipe it with your palm or the eraser to reveal the answer, or Undo. Tap ▾ ▸ Highlight to go back to the see-through highlighter; the Highlight strength slider there (10–100%) makes highlights lighter or bolder, and printed text stays black at any strength. Covers export as solid bars, but the text under them is still in the exported PDF (anyone can copy it), so OverBoard tells you when you export.
• Clear page clears the page you're looking at; Clear all clears every page (tap twice). A PDF with a chapter list has Chapters in that row instead, and Clear ▸ opens the same two choices beside it. Both clear only the current class period, and Undo brings it back. A one-page PDF just has Clear (tap twice).
• Big books are fine. Only the pages near the screen are drawn, so a 600-page textbook scrolls smoothly. Type a page number in the box, or tap Chapters if the PDF has a table of contents.
• Zoom with − / Fit / +, or pinch on a trackpad. Ink stays on the page at any zoom.
• Text and links work like a normal PDF reader in Scroll mode: drag across text to select and copy it (scanned PDFs too, if they were OCR'd), tap a link in a contents page to jump there, and web links open in a new tab. In Write mode the pen, palm and finger work exactly as before; the text never gets in the way.
• Find text (Settings & help ▸ Find text…, or Ctrl/⌘+F) searches every page of the PDF, not just the ones on screen. Tap a result to jump to it.
• Ink saves automatically in this browser, matched to the exact PDF file. The PDF is kept too, so it's under Open again next time. If the page reloads, the PDF reopens where you were, with every stroke.
• Export PDF downloads a copy of the PDF with the current period's ink drawn in as sharp vector lines, named for the period (Moby_Dick_annotated_P1.pdf). Share it, print it, or post it to your class. The original text and links stay in it, so it can still be searched and copied.
• Save ink / Load ink moves your ink between computers as a small .overboard.json file. Open the same PDF on the other computer, then load (or drop) the ink file.
• Save ink into PDF (optional, off until you turn it on) keeps all periods' ink inside a PDF file you choose, by default a new Name_board.pdf. The pages aren't changed: the ink is added at the end of the file, so other apps show the plain PDF. Open that file in OverBoard on any computer and keep writing. In Chrome or Edge it then saves into the file automatically; tap the button again to stop. Other browsers get a one-time download.

Word files: in Word, choose File → Save as PDF, then open the PDF.

Start from a blank page

No PDF? Under the drop box, tap Blank, Lined, Graph, Dots or Isometric to start a one-page notebook on that paper (US Letter; lined is wide ruled with a red margin; graph, dots and isometric triangles are ¼ inch apart).

• Add a page: scroll past the last page and tap a paper to add a page at the end, or tap Pages ▸ on the toolbar to add one right after the page you're on. Each new page can be a different paper.
• Remove a page: Pages ▸ Remove this page (tap twice). Its ink goes with it, in every class period; ink on the other pages stays where it was. Undo can't bring a removed page back.
• A notebook has Pages ▸ | Clear ▸ where a book has Chapters. Everything else works the same: it's under Open again (which keeps your 12 latest PDFs and, separately, your 12 latest notebooks, so notebooks never push PDFs off the list), Export PDF (Settings & help ▸) saves it as a normal PDF with the paper and the current period's ink drawn in (an empty notebook exports too, as printable paper), and Save ink into PDF keeps the whole notebook in one file you can open on another computer.

Install it (works offline)

After you've opened the app once, it keeps a complete copy of itself in the browser, so it opens, opens PDFs, takes ink and exports with no internet (a dropped Wi-Fi in class doesn't matter).

To install it on a Mac with Chrome: open the app and click Install app on the start screen (or the install icon at the right end of the address bar). OverBoard PDF then opens in its own window and lives in Launchpad and ~/Applications/Chrome Apps; drag it to the Dock to keep it there. To open a PDF from Finder, right-click it ▸ Open With ▸ OverBoard PDF (Chrome asks once whether to allow it). Edge on Windows works the same way. Uninstall from the app window's ⋮ menu.

Updates install themselves: a new version downloads in the background in full, then switches the next time you open OverBoard (if another OverBoard window or tab is open, after you close them all). Your ink and the PDFs under Open again are kept.

Everything the app needs, including the PDF reader (PDF.js) and pdf-lib for Export PDF, comes from this site (bpmdata.github.io), so it works behind school web filters that block other sites.

Use it on your own worksheets (HTML)

Option 1: in the browser (easiest, works on school laptops). Open the app and drop your .html file on it. It saves a Name_board.html copy with OverBoard added (or upgraded, keeping saved ink), and your original is left alone. Double-click the copy to open it. Nothing to install, so it works on locked-down Windows laptops. (If the worksheet uses pictures stored as separate files, the app tells you to keep the copy in the same folder as the original.)

Option 2: the desktop installer, for converting a whole folder at once. Download this repo, then double-click:

• Mac: overlay/Ink Overlay Installer.command
• Windows: overlay/Ink Overlay Installer.bat (needs Python 3, which many district laptops don't allow; use Option 1 instead)

Pick your .html files. By default the installer makes a Name_board.html copy for the board and leaves your original alone. If a file already has an older OverBoard, it upgrades it and keeps any ink saved inside.

From a terminal:

python3 overlay/ink_overlay_installer.py worksheet.html --open

The toolbar matches the PDF app's: − / Fit / + zoom the worksheet but not the toolbar (ink stays on the page; Ctrl+scroll or a trackpad pinch works too), Clear page | Clear all (a worksheet without .page sections gets one Clear), and Settings & help ▸ holds Save PDF, Save ink into file, Change linked file, Move toolbar, Settings… and Board not working?.

Option 3: paste it in. Copy everything in overlay/ink_overlay.html and paste it just before </body> in any HTML file.

Worksheets built from fixed-size .page elements (like <div class="page"> at 8.5×11 in) get page-by-page jumping, Clear page, Fit zoom and PDF output. Other pages still work and print as one long sheet.

For contributors

• app/ is the PDF app: plain ES modules, served as-is (open http://localhost:8000/app/ after python3 -m http.server).

• The PDF app and the HTML overlay always have the same features. A toolbar button, shortcut or behavior added to one goes into the other in the same pull request (bump the overlay's version in its first line).

• shared/ink-core.js (drawing, smoothing, pen/palm/finger rules, keyboard shortcuts, toolbar helpers) and shared/toolbar.css are used by both the PDF app and the overlay.

• After editing anything in app/ or shared/, run python3 tools/build.py. It copies the shared code into the paste-in overlay (which must stay one self-contained file) and the demo page, and updates the app's version stamp (app/version.json), so browsers never mix old and new files after an update. --check fails if you forgot.

• Offline copy. app/sw.js (a service worker) caches every file in app/ and shared/. tools/build.py writes the file list at its top, with each file's SHA-256, so it can't go out of date (--check catches it). A new version is only used once every file has downloaded and matches; it switches in one step and then the old copy is deleted. The manifest is app/manifest.json; icons are drawn by tools/make_icons.py.

• Libraries (PDF.js, pdf-lib) live in app/vendor/, so the app works behind school web filters that block CDNs. Versions are pinned in app/libs.js; after changing one, run python3 tools/vendor_libs.py (downloads from npm and verifies checksums).

• Tests run in a real browser (Playwright): pen, palm, finger, highlighter, zoom alignment, text selection and links, search, saving, ink files, Export PDF (and that it keeps the PDF's text), Save ink into PDF, HTML board copies, the overlay, and offline use and updates.

  npm install
  npx playwright install chromium
  npm test

  They run on every pull request (.github/workflows/test.yml), along with both --checks. Test PDFs are in tests/fixtures/.

Smartboard tips

• Turn off the board's own ink tool so it doesn't fight OverBoard. On a Mac with SMART software, this stops SMART Ink from starting:

  launchctl disable gui/$(id -u)/com.smarttech.ink

  Keep the board's drivers installed. They're what let OverBoard tell your palm apart from the pen.

• Board not working? Choose Settings & help ▸ Board not working? (or the link at the bottom of the app's start screen). A two-minute check asks you to draw with your finger and the pen and wipe with your hand, then sends what your board reported so OverBoard can be fixed for boards like yours. Nothing is sent until you press Send.

• For developers: tools/board-probe.html shows live what the browser (and the SMART driver, if present) report for pen, finger and palm, including the driver's raw contact points.

• Holding a finger still on some SMART Boards is swallowed by the driver until you move. Pen holds work everywhere.

Privacy

No accounts, no uploads; your ink stays on your machine.

• OverBoard has no server. Ink, and PDFs you open in the app, are stored in your browser, and inside your own file if you choose.
• The one exception is Board not working?, and only when you press Send on its last screen, after it shows you everything it will send. It sends your board's brand and model, your browser, operating system and screen size, and what the board reported while you drew (pen, mouse or touch; size; pressure). Never worksheets, PDFs, ink or file names. It becomes a public GitHub issue; the optional email address and comments go only to OverBoard's reports inbox. A teacher who gives an email gets a thank-you right away and one more email when there's a fix to try, and nothing else. (Setup: docs/REPORTS.md.)
• What does get downloaded: the web pages (kept in the browser for offline use) and the two open-source libraries the PDF app uses (PDF.js and pdf-lib), all from GitHub Pages (bpmdata.github.io). Your PDFs, worksheets and ink are never sent anywhere. (The board-probe diagnostic page also loads one script from cdnjs.)
• The optional desktop installer is a Python script that runs on your computer and only edits the files you pick.

Contributing

Issues and pull requests are welcome, especially reports from boards other than SMART (Promethean, ViewSonic, Surface, iPad). The easiest way is Settings & help ▸ Board not working? on the board itself.

License

Copyright (C) 2026 Bryan Murphy. OverBoard's code is licensed under the GNU Affero General Public License v3.0 (AGPLv3): you may use, change and share it, but if you share a changed version, or run one as a website or online service, you must share its source code under AGPLv3 too. (Until Oct 26, 2026 it was MIT; copies taken before then keep that license.)

What you make with it (your worksheets, your ink, the PDFs you save) is yours to license however you like; the code inside stays AGPLv3. The bundled libraries keep their own licenses (app/vendor/*/LICENSE*: pdf.js under Apache 2.0, pdf-lib under MIT).

SMART Board is a trademark of SMART Technologies. OverBoard is an independent project and is not affiliated with or endorsed by them.