Understanding Unity WebGL's .data File and Options for Parsing

When developing games with Unity for WebGL deployment, you might notice a .data file generated alongside your build. This file plays a crucial role in how your game functions in a web environment. So, what exactly is the .data file, and what format does it use?

The Role and Format of the .data File

The .data file in a Unity WebGL build is a proprietary binary file that Unity creates to package all the essential resources your game needs at runtime. This includes scenes, assets, textures, audio, and compiled scripts. Here are some key points about the .data file:

• Binary Format: It's a binary file, meaning it's not human-readable and is optimized for machine interpretation.
• Resource Packaging: Unity consolidates all game resources into this single file to streamline the loading process in web browsers.
• Optimized Loading: By packaging resources this way, Unity reduces the number of HTTP requests needed, improving load times and performance.
• Integration with WebGL Runtime: The Unity WebGL runtime scripts (UnityLoader.js or newer versions with *.framework.js and *.wasm files) handle the loading and interpretation of the .data file during game execution.

Extract Resources from Unity .data File

Tools

• UABE with wasm support can extract the .data build ouput (the extrating result cotainers data.unity3d and global-metadata.dat files)
• use AssetRipper to extract the resources from data.unity3d and global-metadata.dat (AssetRipper also allows you to extract unity resources from androind apk directly!)

Python script

This is not a good option

UnityPack can parse .data file, and from them, obtain data.unity3d file. It supports parsing older versions of .unity3d files, allowing you to extract images, sounds, meshes, and other resources. However, UnityPack is no longer maintained. For newer versions of Unity, you can use UnityPy to parse data.unity3d files.