Note: This feature is available in Web Workers.
PerformanceMark is an interface for PerformanceEntry objects with an entryType of "mark".
Entries of this type are typically created by calling performance.mark() to add a named DOMHighResTimeStamp (the mark) to the browser's performance timeline. To create a performance mark that isn't added to the browser's performance timeline, use the constructor.
PerformanceMark()Creates a new PerformanceMark object that isn't added to the browser's performance timeline.
PerformanceMark.detailContains arbitrary metadata about the measure.
This interface extends the following PerformanceEntry properties by qualifying/constraining the properties as follows:
PerformanceEntry.entryType Read onlyReturns "mark".
PerformanceEntry.name Read onlyReturns the name given to the mark when it was created via a call to performance.mark().
PerformanceEntry.startTime Read onlyReturns the DOMHighResTimeStamp when performance.mark() was called.
PerformanceEntry.duration Read onlyReturns 0. (A mark has no duration.)
This interface has no methods.
See the example in Using the User Timing API.
Chrome DevTools uses performance.mark() and in particular a structured detail property as part of its extensibility API that surfaces these in custom tracks in performance traces. See the example in Performance: mark() method page and the Chrome's extensibility API documentation for more information and examples.