How to access browser audio as a Unity AudioSource, change the volume, or mute audio?

Accessing browser audio as a Unity AudioSource

The browser engines used by 3D WebView all currently output audio directly to the system, so audio isn't accessible as a Unity AudioSource. I plan to update 3D WebView for Windows and macOS in the future to expose audio as an AudioSource, and I'll update this page when that feature's ready. Unfortunately, it's unlikely that I'll be able to expose audio as an AudioSource on other platforms (e.g. Android, iOS) because the browser engines for other platforms don't provide a mechanism to access audio data. However, your application can still manipulate browser audio using the approaches described below.

Changing volume

Although 3D WebView doesn't currently have C# APIs specifically for setting the volume level, you can use IWebView.ExecuteJavaScript() to run JavaScript that sets the volume of media on the page. For example, the following code sets the volume of all media elements on the page to 25%:

webViewPrefab.WebView.ExecuteJavaScript(
  "document.querySelectorAll('video, audio').forEach(mediaElement => mediaElement.volume = 0.25)"
);

For more information about how to manipulate media elements with JavaScript, please see MDN's HTMLMediaElement documentation.

Muting audio

Some of the 3D WebView packages support the IWithMutableAudio interface, which can be to mute browser audio.