PerformanceEntry - Web APIs | MDN
Instance properties
PerformanceEntry.nameRead only-
A string representing the name for a performance entry. The value depends on the subtype.
PerformanceEntry.entryTypeRead only-
A string representing the type of performance metric. For example,
"mark"whenPerformanceMarkis used. PerformanceEntry.startTimeRead only-
A
DOMHighResTimeStamprepresenting the starting time for the performance metric. PerformanceEntry.durationRead only-
A
DOMHighResTimeStamprepresenting the duration of the performance entry.
Instance methods
PerformanceEntry.toJSON()-
Returns a JSON representation of the
PerformanceEntryobject.
Example
Working with performance entries
The following example creates PerformanceEntry objects that are of the types PerformanceMark and PerformanceMeasure.
The PerformanceMark and PerformanceMeasure subclasses inherit the duration, entryType, name, and startTime properties from PerformanceEntry and set them to their appropriate values.
js
// Place at a location in the code that starts login
performance.mark("login-started");
// Place at a location in the code that finishes login
performance.mark("login-finished");
// Measure login duration
performance.measure("login-duration", "login-started", "login-finished");
function perfObserver(list, observer) {
list.getEntries().forEach((entry) => {
if (entry.entryType === "mark") {
console.log(`${entry.name}'s startTime: ${entry.startTime}`);
}
if (entry.entryType === "measure") {
console.log(`${entry.name}'s duration: ${entry.duration}`);
}
});
}
const observer = new PerformanceObserver(perfObserver);
observer.observe({ entryTypes: ["measure", "mark"] });
Specifications
| Specification |
|---|
| Performance Timeline # dom-performanceentry |