In general, the 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 performance is close to native apps on the GPU, because the WebGL graphics API uses your GPU for hardware-accelerated rendering. The only exception is the slight overhead for translating WebGL API calls and shadersA program that runs on the GPU. More info
See in Glossary to your OS graphics API (typically DirectX on Windows, OpenGL on Mac, and Linux).
On the CPU, Emscripten translates your code into WebAssembly, the performance of which depends on the web browser you’re using.
Following are the additional considerations that you must be aware of:
Tip: To learn how Unity distributes work to different threads on non-WebGL platforms, refer to the new timeline ProfilerA window that helps you to optimize your game. It shows how much time is spent in the various areas of your game. For example, it can report the percentage of time spent rendering, animating, or in your game logic. More info
See in Glossary in Unity.
To improve performance, set Exception support to None in the Player settings for WebGL by expanding Other Settings > Stack Trace.
WebGL supports the Unity profiler. Refer to the Profiler documentation to learn how to set it up.
Your content continues to run when the canvas or browser window loses focus if one of the following options is enabled:
However, some browsers can throttle content running in background tabs. If the tab with your content isn’t visible, your content only updates once per second in most browsers. Note that this causes Time.time to progress slower than usual with the default settings, as the default value of Time.maximumDeltaTime is lower than one second.
You might want to run your WebGL content at a lower frame rate in some situations to reduce CPU usage. For example, on other platforms, you can use the Application.targetFrameRate API to do so.
When you don’t want to throttle performance, set this API to the default value of –1. This allows the browser to adjust the frame rate for the smoothest animation in the browser’s render loop, and might produce better results than Unity trying to do its own main loop timing to match a target frame rate.
Note: For security reasons, Unity can’t query a browser for its frame rate. As a result, Unity assumes a display rate of 60 fpsSee first person shooter, frames per second.
See in Glossary for all browsers and bases Application.targetFrameRate
on that value.