The start() method of the AudioBufferSourceNode Interface is used to schedule the start of the audio buffer playback.


var source = audioCtx.createBufferSource();
source.start(audioCtx.currentTime + 1,3,10);


The most simple example just starts the audio buffer playing from the beginning — you don't need to specify any parameters in this case:


The following more complex example will start playing, after 1 second pause, a 10 second snippet of an audio buffer 3 seconds into the audio duration.

source.start(audioCtx.currentTime + 1,3,10);

Note: For a more complete example showing start() in use, check out our AudioContext.decodeAudioData example, You can also run the code example live, or view the source.




The when parameter defines when the play will start. If when represents a time in the past, the play will start immediately. If the method is called more than one time, or after a call to AudioBufferSourceNode.stop(), an exception is raised.
The offset parameter, which defaults to 0, defines where the playback will start.
The duration parameter, which defaults to the length of the asset minus the value of offset, defines the length of the portion of the asset to be played.


Specification Status Comment
Web Audio API
The definition of 'start()' in that specification.
Working Draft  

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 14 webkit 23 Not supported 15 webkit
22 (unprefixed)
6 webkit
Feature Android Chrome Firefox Mobile (Gecko) Firefox OS IE Phone Opera Mobile Safari Mobile
Basic support Not supported 28 webkit 25 1.2 Not supported Not supported webkit

See also


© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.