Skip to content


Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
A thin wrapper around the Web Audio API that takes an <audio> element and gives you its waveform/frequency data in return.
JavaScript C
branch: master


latest commit 3efe6e7da1
@hughsk authored
Failed to load latest commit information.
shaders first commit
.gitignore first commit first commit Add "stereo" and "audible" options
demo.js Add "stereo" and "audible" options
index.html first commit
index.js Add "stereo" and "audible" options
package.json 2.0.0

web-audio-analyser experimental

A thin wrapper around the Web Audio API that lets you take some audio and get its waveform/frequency data in return.



analyser = require('web-audio-analyser')(audio[, ctx][, opts])

Takes some form of audio as the first argument. This may be one of the following:

  • An <audio> element.
  • A MediaStream object created by calling getUserMedia.
  • Any kind of AudioSourceNode.

Optionally, you can pass in your own AudioContext instance too. Note there may only be one instance of this per page, and if not supplied one will be created for you.

You can also use the following options:

  • stereo: retrieve separate data from the left and right audio channels.
  • audible: whether or not to play the audio you're analysing. Defaults to true, but set this to false to disable. You can use analyser.output to pass the resulting output elsewhere.

analyser.waveform([ui8array][, channel])

Copies the audio's current time-domain data into a Uint8Array. If you don't pass your own in, one will be created for you: this will be reused, so it's safe to call in an animation loop.

If you've enabled the stereo option, you should pass channel as either 0 or 1 to retrieve output from the left and right channels respectively.

analyser.frequencies([ui8array][, channel])

Much like analyser.waveform, with the exception of copying the audio's currrent frequency data into a Uint8Array.

Something went wrong with that request. Please try again.