The PerformanceMark() constructor creates a timestamp with the given name.

Unlike performance.mark(), performance marks created by the constructor aren't added to the browser's performance timeline. This means that calls to the Performance interface's getEntries*() methods (getEntries(), getEntriesByName() or getEntriesByType()) won't show entries for these marks.

name

A string representing the name of the mark.

markOptions Optional

An object for specifying a timestamp and additional metadata for the mark.

detail Optional

Arbitrary metadata to include in the mark. Defaults to null.

startTime Optional

DOMHighResTimeStamp to use as the mark time. Defaults to performance.now().

A PerformanceMark object.

• SyntaxError: Thrown if the name given to this method already exists in the PerformanceTiming interface.
• TypeError: Thrown if startTime is negative.

The following example shows how PerformanceMark entries are constructed and then aren't part of the browser's performance timeline.

new PerformanceMark("squirrel");
new PerformanceMark("monkey");
new PerformanceMark("dog");

const allEntries = performance.getEntriesByType("mark");
console.log(allEntries.length);
// 0

• performance.mark()