Building your WebGL application

To create a build for WebGL, go to File > Build Settings from Unity’s main menu. In the Platform list, select WebGL and then click Switch Platform.

When you have configured the Build Settings, choose from the following two options:

• Build builds your application into a Player.
• Build and Run builds your application in a Player, and opens that Player on your target platform.

The Unity build system for WebGLA JavaScript API that renders 2D and 3D graphics in a web browser. The Unity WebGL build option allows Unity to publish content as JavaScript programs which use HTML5 technologies and the WebGL rendering API to run Unity content in a web browser. More info
See in Glossary supports the following settings:

For changing the settings for Asset Import Overrides, see Build Settings.

Build Folder

The Build folder contains the following files ([ExampleBuild] represents the name of the target build folder).

If you enable a Compression Method for your build, Unity identifies the extension that corresponds with the compression method and adds this extension to the names of the files inside the Build subfolder. If you enable Decompression Fallback, Unity appends the extension .unityweb to the build file names. Otherwise, Unity appends the extension .gz for the Gzip compression method, or .br for the Brotli compression method. For more information, see WebGL: Compressed builds and server configuration.

If you enable Name Files As Hashes in the Player Settings, Unity uses the hash of the file content instead of the default filename. This applies to each file in the build folder. This option allows you to upload updated versions of the game builds into the same folder on the server, and only upload the files which have changed between build iterations.

Note: Opening a Player directly from the file system might not work in some browsers. This is due to security restrictions applied to local file URLs.

Deep Profiling Support

Enable the Deep Profiling Support setting to make the Unity Profiler profile every function call in your application. For more information see the documentation on Deep Profiling.

Player settings

WebGL has some additional options in the Player settings (menu: Edit > Project SettingsA broad collection of settings which allow you to configure how Physics, Audio, Networking, Graphics, Input and many other areas of your project behave. More info
See in Glossary, then select the Player category).

Other Settings

Strip Engine Code

Open Other Settings to access the Strip Engine Code option. This option is checked by default to enable code stripping for WebGL. With this option checked, Unity does not include code for any classes you don’t use. For example, if you don’t use any physics components or functions, the whole physics engineA system that simulates aspects of physical systems so that objects can accelerate correctly and be affected by collisions, gravity and other forces. More info
See in Glossary is removed from your build. See the Stripping section below for more details.

Publishing Settings

Enable Exceptions

Open Publishing Settings to access Enable Exceptions. Enable Exceptions allows you to specify how unexpected code behavior (generally considered errors) is handled at run time. It has these options:

• None: Select this if you don’t need any exception support. This gives the best performance and smallest builds. With this option, any exception thrown causes your content to stop with an error in that setting.
• Explicitly Thrown Exceptions Only (default): Select this to capture exceptions which are explicitly specified from a throw statement in your scriptsA piece of code that allows you to create your own Components, trigger game events, modify Component properties over time and respond to user input in any way you like. More info
  See in Glossary and to also ensure finally blocks are called. Note that selecting this option makes the generated JavaScript code from your scripts longer and slower; This might only be an issue if scripts are the main bottleneck in your project.
• Full Without Stacktrace: Select this option to capture:
  • Exceptions which are explicitly specified from throw statements in your scripts (the same as in the Explicitly Thrown Exceptions Only option)
  • Null References
  • Out of Bounds Array accesses
• Full With Stacktrace: This option is similar to the option above but it also captures Stack traces. Unity generates these exceptions by embedding checks for them in the code, so this option decreases performance and increases browser memory usage. Only use this for debugging, and always test in a 64-bit browser.

Select Publishing Settings to access Data Caching.

Data Caching

To access Data Caching, go to Publishing Setings via File > Build Settings > Player Settings > WebGL. This enables the browser to cache the main data files into the IndexedDB database.

Using the default browser HTTP cache does not guarantee that the browser caches a particular response. This is because the browser HTTP cache has limited space, and the browser might not be able to cache files that are too large.

To improve your loading speed, IndexedDB allows you to cache files above the browser limit. When you cache more files, you increase the chance that downloaded content is available on the user’s machine during the next run of the build.

Data Caching only caches the .data files in the IndexedDB cache for HTTP responses. To cache AssetBundles, you need to enable Data Caching and override unityInstance.Module.cacheControl(). To do this, make sure Module.cacheControl(url) returns must-revalidate for the requested AssetBundle URL. For example, you can override the unityInstance.Module.cacheControl() function in the fulfillment callback of the Promise that createUnityInstance() returns. For further information on createUnityInstance() see WebGL: Compressed builds and server configuration.

• Removed asm.js linker target in Unity 2019.1
• Build file updates and Data Caching added in Unity 2020.1