PerformanceEntry: duration property

Available in workers

The read-only duration property returns a timestamp that is the duration of the performance entry. The meaning of this property depends on the value of this entry’s entryType.

Value

A DOMHighResTimeStamp representing the duration of the performance entry. If the duration concept doesn’t apply for a particular performance metric, a duration of 0 is returned.

The meaning of this property depends on the value of this performance entry’s entryType:

• event
  • : The time from the event’s startTime to the next rendering paint (rounded to the nearest 8ms).
• first-input
  • : The time from the first input event’s startTime to the next rendering paint (rounded to the nearest 8ms).
• longtask
  • : The elapsed time between the start and end of task, with a 1ms granularity.
• measure
  • : The duration of the measure.
• navigation
  • : The difference between the entry’s loadEventEnd and startTime properties.
• resource
  • : The entry’s responseEnd value minus the entry’s startTime value.

For the following entry types, duration is not applicable, and in this case the value is always 0:

• element
• largest-contentful-paint
• layout-shift
• mark
• paint
• taskattribution
• visibility-state

Examples

Using the duration property

The following example logs all observed performance entries with a duration larger than 0.

function perfObserver(list, observer) {
  list.getEntries().forEach((entry) => {
    if (entry.duration > 0) {
      console.log(`${entry.name}'s duration: ${entry.duration}`);
    }
  });
}
const observer = new PerformanceObserver(perfObserver);
observer.observe({ entryTypes: ["measure", "mark", "resource"] });

Specifications

Browser compatibility