IdleDeadline

The IdleDeadline interface is used as the data type of the input parameter to idle callbacks established by calling Window.requestIdleCallback(). It offers a method, timeRemaining(), which lets you determine how much longer the user agent estimates it will remain idle and a property, didTimeout, which lets you determine if your callback is executing because its timeout duration expired.

To learn more about how request callbacks work, see Collaborative Scheduling of Background Tasks.

Properties

IdleDeadline.didTimeout Read only
A Boolean whose value is true if the callback is being executed because the timeout specified when the idle callback was installed has expired.

Methods

IdleDeadline.timeRemaining()
Returns a DOMHighResTimeStamp, which is a floating-point value providing an estimate of the number of milliseconds remaining in the current idle period. If the idle period is over, the value is 0. Your callback can call this repeatedly to see if there's enough time left to do more work before returning.

Example

See our complete example in the article Cooperative Scheduling of Background Tasks API.

Specifications

Specification Status Comment
Cooperative Scheduling of Background Tasks Proposed Recommendation

Browser compatibility

DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
IdleDeadlineChrome Full support 47Edge Full support 79Firefox Full support 55
Full support 55
Full support 53
Disabled
Disabled From version 53: this feature is behind the dom.requestIdleCallback.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
IE No support NoOpera Full support 34Safari No support NoWebView Android Full support 47Chrome Android Full support 47Firefox Android Full support 55
Full support 55
Full support 53
Disabled
Disabled From version 53: this feature is behind the dom.requestIdleCallback.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
Opera Android Full support 34Safari iOS No support NoSamsung Internet Android Full support 5.0
didTimeoutChrome Full support 47Edge Full support 79Firefox Full support 55
Full support 55
Full support 53
Disabled
Disabled From version 53: this feature is behind the dom.requestIdleCallback.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
IE No support NoOpera Full support 34Safari No support NoWebView Android Full support 47Chrome Android Full support 47Firefox Android Full support 55
Full support 55
Full support 53
Disabled
Disabled From version 53: this feature is behind the dom.requestIdleCallback.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
Opera Android Full support 34Safari iOS No support NoSamsung Internet Android Full support 5.0
timeRemainingChrome Full support 47Edge Full support 79Firefox Full support 55
Full support 55
Full support 53
Disabled
Disabled From version 53: this feature is behind the dom.requestIdleCallback.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
IE No support NoOpera Full support 34Safari No support NoWebView Android Full support 47Chrome Android Full support 47Firefox Android Full support 55
Full support 55
Full support 53
Disabled
Disabled From version 53: this feature is behind the dom.requestIdleCallback.enabled preference (needs to be set to true). To change preferences in Firefox, visit about:config.
Opera Android Full support 34Safari iOS No support NoSamsung Internet Android Full support 5.0

Legend

Full support
Full support
No support
No support
User must explicitly enable this feature.
User must explicitly enable this feature.

See also