D2R File Extractor

A WPF desktop app with easy 1-click extraction of Diablo 2: Resurrected CASC game archives for faster load times. Also lets you undo the extraction before game updates and easily re-apply the extraction after updating.

⬇️ Download D2RExtractor v1.1.4 (Standalone ZIP)

YouTube Installation & Usage Guide

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How it works

D2R normally loads assets from compressed CASC archives at runtime. By pre-extracting the data\global\, data\hd\, and data\local\ folders to plain files, the game loads them directly — dramatically reducing load times.

This app automates that process for one or more D2R installations and keeps a manifest of every extracted file so the extraction can be fully reversed.

This app uses Ladislav Zezula's native CascLib library — the same engine that powers Ladik's CASC Viewer.

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Prerequisites

Disk space

Extraction writes ~40–45 GB of data per D2R installation. More if also extracting international files. Ensure sufficient free space.

Steam installations

Steam D2R installations (patch 3.1.2+) are fully supported. The app automatically detects when the standard CASC open fails and falls back to CDN-enabled mode. An internet connection is required during extraction for Steam users — game data is downloaded from Blizzard's CDN. Extraction time will depend on your download speed.

The bundled CascLib.dll includes patches for the Steam D2R CASC layout. See CascLib issue #285 for upstream context.

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Build

dotnet build D2RExtractor.sln -c Release -p:Platform=x64

Output: D2RExtractor\bin\x64\Release\net8.0-windows\D2RExtractor.exe

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Usage

1. Launch D2RExtractor.exe
2. Click + Add Installation and select your D2R base folder (the one containing the Data subfolder) - Repeat for any additional D2R folders.
3. Click the Gear icon at the top right corner for settings. This allows for extraction of international files (multi-language dubbing) if needed.
4. Click Extract — extraction runs in the background (Battle.net: ~30–45 min; Steam: depends on download speed)
5. Launch D2R with the "-direct -txt" command line options and enjoy faster load times.

Before updating D2R

1. Click Undo Extraction — removes all extracted files using the saved manifest
2. Update D2R normally via your game launcher
3. Re-extract after the update

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File layout

D2RExtractor\
├── D2RExtractor.sln
└── D2RExtractor\
    ├── App.xaml(.cs)
    ├── MainWindow.xaml(.cs)
    ├── Models\
    │   ├── D2RInstallation.cs       Observable model for each managed installation
    │   └── ExtractionManifest.cs    Per-install record of extracted files
    ├── Services\
    │   ├── CascExtractorService.cs  CASC open / extract / undo logic
    │   └── ManifestService.cs       JSON settings + manifest persistence
    ├── Native\
    │   └── CascLib.cs               P/Invoke declarations for CascLib.dll
    └── Tools\
        └── CascLib.dll              (place your copy here before building)

Settings are stored in: %AppData%\D2RExtractor\settings.json Manifests are stored in: <D2RPath>\data\.extraction_manifest.json