/Web APIs


The OscillatorNode interface represents a periodic waveform, such as a sine wave. It is an AudioScheduledSourceNode audio-processing module that causes a specified frequency of a given wave to be created—in effect, a constant tone.

EventTarget AudioNode AudioScheduledSourceNode OscillatorNode
Number of inputs 0
Number of outputs 1
Channel count mode max
Channel count 2 (not used in the default count mode)
Channel interpretation speakers



Creates a new instance of an OscillatorNode object, optionally providing an object specifying default values for the node's properties. As an alternative, you can use the BaseAudioContext.createOscillator() factory method; see Creating an AudioNode.

Instance properties

Inherits properties from its parent, AudioScheduledSourceNode, and adds the following properties:


An a-rate AudioParam representing the frequency of oscillation in hertz (though the AudioParam returned is read-only, the value it represents is not). The default value is 440 Hz (a standard middle-A note).


An a-rate AudioParam representing detuning of oscillation in cents (though the AudioParam returned is read-only, the value it represents is not). The default value is 0.


A string which specifies the shape of waveform to play; this can be one of a number of standard values, or custom to use a PeriodicWave to describe a custom waveform. Different waves will produce different tones. Standard values are "sine", "square", "sawtooth", "triangle" and "custom". The default is "sine".

Event handlers


Sets the event handler for the ended event, which fires when the tone has stopped playing.

Instance methods

Inherits methods from its parent, AudioScheduledSourceNode, and adds the following:


Sets a PeriodicWave which describes a periodic waveform to be used instead of one of the standard waveforms; calling this sets the type to custom.


Specifies the exact time to start playing the tone.


Specifies the time to stop playing the tone.


The following example shows basic usage of an AudioContext to create an oscillator node and to start playing a tone on it. For an applied example, check out our Violent Theremin demo (see app.js for relevant code).

// create web audio api context
const audioCtx = new (window.AudioContext || window.webkitAudioContext)();

// create Oscillator node
const oscillator = audioCtx.createOscillator();

oscillator.type = "square";
oscillator.frequency.setValueAtTime(440, audioCtx.currentTime); // value in hertz


Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
OscillatorNode 55 79 53 No 42 14.1 55 55 53 42 14.5 6.0
OscillatorNode 20 12 25 No 15 6 4.4 25 25 14 6 1.5
detune 20 12 25 No 15 6 4.4 25 25 14 6 1.5
frequency 20 12 25 No 15 6 4.4 25 25 14 6 1.5
setPeriodicWave 30 12 25 No 17 8 ≤37 30 25 18 8 2.0
type 20 12 25 No 15 6 4.4 25 25 14 6 1.5

See also

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