The currentTime
read-only property of the BaseAudioContext
interface returns a double representing an ever-increasing hardware timestamp in seconds that can be used for scheduling audio playback, visualizing timelines, etc. It starts at 0.
Syntax
var curTime = baseAudioContext.currentTime;
Example
var AudioContext = window.AudioContext || window.webkitAudioContext; var audioCtx = new AudioContext(); // Older webkit/blink browsers require a prefix ... console.log(audioCtx.currentTime);
Reduced time precision
To offer protection against timing attacks and fingerprinting, the precision of audioCtx.currentTime
might get rounded depending on browser settings.
In Firefox, the privacy.reduceTimerPrecision
preference is enabled by default and defaults to 20us in Firefox 59; in 60 it will be 2ms.
// reduced time precision (2ms) in Firefox 60 audioCtx.currentTime; // 23.404 // 24.192 // 25.514 // ... // reduced time precision with `privacy.resistFingerprinting` enabled audioCtx.currentTime; // 49.8 // 50.6 // 51.7 // ...
In Firefox, you can also enabled privacy.resistFingerprinting
, the precision will be 100ms or the value of privacy.resistFingerprinting.reduceTimerPrecision.microseconds
, whichever is larger.
Specifications
Specification | Status | Comment |
---|---|---|
Web Audio API The definition of 'currentTime' in that specification. |
Working Draft | Initial definition. |
Browser compatibility
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
currentTime | Chrome
Full support
10
| Edge Full support ≤18 | Firefox
Full support
53
| IE No support No | Opera
Full support
22
| Safari
Full support
6
| WebView Android Full support Yes | Chrome Android Full support 33 | Firefox Android
Full support
53
| Opera Android
Full support
22
| Safari iOS
Full support
6
| Samsung Internet Android Full support 2.0 |
Legend
- Full support
- Full support
- No support
- No support
- See implementation notes.
- See implementation notes.
- Requires a vendor prefix or different name for use.
- Requires a vendor prefix or different name for use.