Baseline Widely available
Note: This feature is available in Web Workers.
The mark() method creates a named PerformanceMark object representing a high resolution timestamp marker in the browser's performance timeline.
mark(name)
mark(name, markOptions)
name
A string representing the name of the mark. Must not be the same name as one of the properties of the deprecated PerformanceTiming interface.
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. Must be structured-cloneable.
startTime Optional
DOMHighResTimeStamp to use as the mark time. Defaults to performance.now().
The PerformanceMark entry that was created.
SyntaxError: Thrown if the name is one of the properties of the deprecated PerformanceTiming interface. See the example below.TypeError: Thrown if startTime is negative.The following example uses mark() to create named PerformanceMark entries. You can create several marks with the same name. You can also assign them, to have a reference to the PerformanceMark object that has been created.
performance.mark("login-started");
performance.mark("login-started");
performance.mark("login-finished");
performance.mark("form-sent");
const videoMarker = performance.mark("video-loaded");
The performance mark is configurable using the markOptions object where you can put additional information in the detail property, which can be of any type.
performance.mark("login-started", {
detail: "Login started using the login button in the top menu.",
});
performance.mark("login-started", {
detail: { htmlElement: myElement.id },
});
The default timestamp of the mark() method is performance.now(). You can set it to a different time using the startTime option in markOptions.
performance.mark("start-checkout", {
startTime: 20.0,
});
performance.mark("login-button-pressed", {
startTime: myEvent.timeStamp,
});
Note in order to maintain backwards compatibility, names that are part of the deprecated PerformanceTiming interface can't be used. The following example throws:
performance.mark("navigationStart");
// SyntaxError: "navigationStart" is part of
// the PerformanceTiming interface,
// and cannot be used as a mark name
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