Version: 2021.3
WebGL Graphics
Embedded Resources on WebGL

Audio in WebGL

This page only provides information about audio capabilities in 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
. To learn how to use audio in your Unity project, see the Audio Overview.

Because Unity uses FMOD to manage audio for platforms, Unity WebGL supports limited audio functionality, which only includes the basic features. FMOD relies on threads, which WebGL doesn’t support. For this reason, Unity uses an implementation based on the internal Web Audio API, which enables the browser to handle audio playback and mixing.

Note: Google Chrome’s new Autoplay policy prevents autoplay of audio and video under certain conditions. For example, while your game might be set to autoplay some background music soon after the game loads, it won’t play automatically unless you click or tap on the website. For more information on how to enable or disable this policy, see Google Chrome’s documentation on Autoplay policy in Chrome.

Supported classes

Unity WebGL supports the following API classes:

Class WebGL Support status
AudioSource WebGL supports some APIs. See AudioSource for specific support details.
AudioListener All APIs supported.
AudioClip WebGL supports some APIs. See AudioClip for specific support details.
SystemInfo.supportsAudio The browser provides audio support for WebGL. For this reason, SystemInfo.supportsAudio is always true.
Microphone Not supported.

AudioSource

The AudioSource API supports basic positional audio playback, including:

  • Pausing and resuming
  • Panning
  • Rolloff
  • Pitch setting
  • Doppler effect support

Unity WebGL supports the following AudioSource APIs:

Properties Summary
Clip Determines the audio clipA container for audio data in Unity. Unity supports mono, stereo and multichannel audio assets (up to eight channels). Unity can import .aif, .wav, .mp3, and .ogg audio file format, and .xm, .mod, .it, and .s3m tracker module formats. More info
See in Glossary
that plays next.
dopplerLevel Sets the Doppler scale for the AudioSource.
ignoreListenerPause Allows AudioSource to ignore AudioListener.pause and continue to play audio.
ignoreListenerVolume Ignores the end-user’s AudioSource volume.
isPlaying Returns true if the AudioSource.clip is playing.
loop Allows the application to loop the AudioSource.clip.
maxDistance Sets the maximum distance at which the AudioSource.clip stops attenuating or becomes inaudible.
minDistance Sets the minimum distance at which the AudioSource.clip no longer rises in volumes. The sound starts to attenuate beyond the minimum distance.
mute Mutes the AudioSource.
pitch Sets the pitch of the AudioSource.clip. WebGL only supports positive pitch values.
playOnAwake Plays the AudioSource on Awake.
rolloffMode Sets the AudioSource attenuation over distance.
time Sets the playback position in seconds.
timeSamples Sets the playback position in Pulse-code modulation (PCM) samples.
velocityUpdateMode Sets whether the AudioSource updates in the fixed or dynamic update loop.
volume Sets the volume of the AudioSource (0.0 to 1.0).
Methods Summary
Pause Pauses the AudioSource.clip.
Play Plays the AudioSource.clip.
PlayDelayed Plays the AudioSource.clip with a delay you specify in seconds.
PlayOneShot Plays an AudioClip and scales the AudioSource volume by volumeScale.
PlayScheduled Plays the AudioSource at a time you specify.
SetScheduledEndTime Sets a time that a scheduled AudioSource.clip ends.
SetScheduledStartTime Sets the time that a scheduled AudioSource.clip starts.
Stop Stops playing the AudioSource.clip.
UnPause Unpauses a paused AudioSource.clip.
PlayClipAtPoint Plays an AudioSource.clip at a given position in the worldspace.

AudioClip

Unity WebGL imports AudioClip files in the AAC Format, which is widely browser supported. Unity WebGL supports the following AudioClip APIs:

Properties Summary
length The length of the AudioClip in seconds.
loadState Returns the current load state of the audio data associated with an AudioClip.
samples The length of the AudioClip in samples.
loadType The load type of the clip. You can set the AudioClip load type in the InspectorA Unity window that displays information about the currently selected GameObject, asset or project settings, allowing you to inspect and edit the values. More info
See in Glossary
.
Method Summary Additional information
AudioClip.Create Creates an AudioClip with a name and length you specify. Unity WebGL partially supports AudioClip.Create. Browsers don’t support dynamic streaming, so to use AudioClip.Create, set the Stream to false.
AudioClip.SetData Sets sample data in an AudioSource.clip. Unity WebGL partially supports AudioClip.SetData. You can only use this method to replace the contents of an AudioClip. On WebGL, Unity ignores the offsetSample parameter.

Compressed Audio

To use compressed audio with WebGL in Unity, set the AudioClip loadType to one of the following options:

CompressionA method of storing data that reduces the amount of storage space it requires. See Texture Compression, Animation Compression, Audio Compression, Build Compression.
See in Glossary
method
Description Considerations
CompressedInMemory Use this to compress the audio on disk and have it remain compressed after it loads into your application memory. Compressed audio can cause latency and is less precise when it comes to audio playback. However, compressed audio uses less memory in your application than decompressed audio. It’s best practise to use CompressedInMemory for audio that’s unaffected by precision for example, background music.
DecompressOnLoad Use this to compress the audio on disk, similar to CompressedInMemory, and decompress when it loads into your application memory. Decompressed audio uses a significant amount of memory compared to compressed audio but has lower latency and more audio flexibility. Use DecompressedOnLoad for audio that’s affected by precision (for example, character dialog or sound effects).

Audio Playback and Browser Security

For security reasons, browsers don’t allow audio playback until an end user interacts with your application webpage via a mouse click, touch event or key press. Use a loading screen to allow the end user to interact with your application and start audio playback before your main content begins.

WebGL Graphics
Embedded Resources on WebGL