IdleDeadline.didTimeout

The read-only didTimeout property on the IdleDeadline interface is a Boolean value which indicates whether or not the idle callback is being invoked because the timeout interval specified when Window.requestIdleCallback() was called has expired.

If didTimeout is true, the IdleDeadline object's timeRemaining() method will return approximately 0.

Idle callbacks support the concept of a timeout in order to ensure that whatever task they're meant to perform actually happens, even if the user agent never has enough idle time available. Your callback will typically check the value of didTimeout if it needs to perform an action even if the browser is too busy to grant you the time; you should react by performing the needed task or, ideally, a minimal amount of work that can be done to keep things moving along, then schedule a new callback to try again to get the rest of the work done.

Syntax

var timedOut = IdleDeadline.didTimeout;

Value

A Boolean which is true if the callback is running due to the callback's timeout period elapsing or false if the callback is running because the user agent is idle and is offering time to the callback.

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

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidiOS SafariSamsung Internet
Basic supportChrome Full support 47Edge No support NoFirefox 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 47Edge Mobile No support NoFirefox 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 37Safari iOS No support NoSamsung Internet Android ?

Legend

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

See also

Document Tags and Contributors

Contributors to this page: fscholz, Sheppy
Last updated by: fscholz,