IdleDeadline.timeRemaining()

This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The timeRemaining() method on the IdleDeadline interface returns the estimated number of milliseconds remaining in the current idle period. The callback can call this method at any time to determine how much time it can continue to work before it must return. For example, if the callback finishes a task and has another one to begin, it can call timeRemaining() to see if there's enough time to complete the next task. If there isn't, the callback can just return immediately, or look for other work to do with the remaining time.

By the time timeRemaining() reaches 0, it is suggested that the callback should return control to the user agent's event loop.

Syntax

timeRemaining = IdleDeadline.timeRemaining();

Return value

A DOMHighResTimeStamp value (which is a floating-point number) representing the number of milliseconds the user agent estimates are left in the current idle period. The value is ideally accurate to within about 5 microseconds.

If the IdleDeadline object's didTimeout property is true, this method returns zero.

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
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