Long tasks

The longtask performance event type and the PerformanceLongTaskTiming API provides information about tasks that occupy the UI thread for 50 milliseconds or more, a metric for input latency, delayed animations, and other sources of "jank." To learn more, see PerformanceLongTaskTiming, PerformanceLongTaskTiming: attribution property, PerformanceLongTaskTiming: toJSON() method, TaskAttributionTiming, TaskAttributionTiming: containerId property, TaskAttributionTiming: containerName property, TaskAttributionTiming: containerSrc property, TaskAttributionTiming: containerType property, TaskAttributionTiming: toJSON() method at MDN.

Compatibility

• Chrome 58 Released on 2017-04-19
• Chrome Android 58 Released on 2017-04-25
• Edge 79 Released on 2020-01-15
• Firefox ❌ See bugzil.la/1348405
• Firefox for Android ❌ See bugzil.la/1348405
• Safari ❌ Search for bugs Search for standards position
• Safari on iOS ❌ Search for bugs Search for standards position