The oversample property of the WaveShaperNode interface is an enumerated value indicating if oversampling must be used. Oversampling is a technique for creating more samples (up-sampling) before applying a distortion effect to the audio signal.

Once applied, the number of samples is reduced to its initial numbers. This leads to better results by avoiding some aliasing, but comes at the expense of a lower precision shaping curve.

The possible oversample values are:

Value Effect
'none' Do not perform any oversampling.
'2x' Double the amount of samples before applying the shaping curve.
'4x' Multiply by 4 the amount of samples before applying the shaping curve.


distortion.oversample = enumeratedValue;


  • distortion is a WaveShaperNode.
  • enumeratedValue is one of 'none', '2x', or '4x'.


The following example shows basic usage of an AudioContext to create a wave shaper node. For applied examples/information, check out our Voice-change-O-matic demo (see app.js for relevant code).

Note: Sigmoid functions are commonly used for distortion curves because of their natural properties. Their S-shape, for instance, helps create a smoother sounding result. We found the below distortion curve code on Stack Overflow.

var audioCtx = new (window.AudioContext || window.webkitAudioContext)();
var distortion = audioCtx.createWaveShaper();


function makeDistortionCurve(amount) {
  var k = typeof amount === 'number' ? amount : 50,
    n_samples = 44100,
    curve = new Float32Array(n_samples),
    deg = Math.PI / 180,
    i = 0,
  for ( ; i < n_samples; ++i ) {
    x = i * 2 / n_samples - 1;
    curve[i] = ( 3 + k ) * x * 20 * deg / ( Math.PI + k * Math.abs(x) );
  return curve;


distortion.curve = makeDistortionCurve(400);
distortion.oversample = '4x';


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

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support141226 No156
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support Yes14 Yes2615 ? Yes

See also

Document Tags and Contributors

 Contributors to this page: fscholz, erikadoyle, teoli, chrisdavidmills
 Last updated by: fscholz,