The timeStamp
read-only property of the Event
interface returns the time (in milliseconds) at which the event was created.
Event.timeStamp
Value
This value is the number of milliseconds elapsed from the beginning of the time origin until the event was created. If the global object is Window
, the time origin is the moment the user clicked on the link, or the script that initiated the loading of the document. In a worker, the time origin is the moment of creation of the worker.
The value is a DOMHighResTimeStamp
accurate to 5 microseconds (0.005 ms), but the precision is reduced to prevent fingerprinting.
Example
HTML
<p> Focus this iframe and press any key to get the current timestamp for the keypress event. </p> <p>timeStamp: <span id="time">-</span></p>
JavaScript
function getTime(event) { var time = document.getElementById("time"); time.firstChild.nodeValue = event.timeStamp; } document.body.addEventListener("keypress", getTime);
Result
Reduced time precision
To offer protection against timing attacks and fingerprinting, the precision of Event.timeStamp
might get rounded depending on browser settings.
In Firefox, the privacy.reduceTimerPrecision
preference is enabled by default and defaults to 2ms.
// reduced time precision (2ms) in Firefox 60 event.timeStamp; // 1519211809934 // 1519211810362 // 1519211811670 // ... // reduced time precision with `privacy.resistFingerprinting` enabled event.timeStamp; // 1519129853500 // 1519129858900 // 1519129864400 // ...
In Firefox, if you also enable privacy.resistFingerprinting
, the precision will be 100ms or the value of privacy.resistFingerprinting.reduceTimerPrecision.microseconds
, whichever is larger.
Specifications
Specification |
---|
DOM Standard # ref-for-dom-event-timestamp① |
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | WebView Android | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | |
timeStamp |
1
Starting with Chrome 49, Firefox 54 and Opera 36, this property returns
DOMHighResTimeStamp instead of
DOMTimeStamp .
|
12
|
1.5
Starting with Chrome 49, Firefox 54 and Opera 36, this property returns
DOMHighResTimeStamp instead of
DOMTimeStamp .
|
9
Starting with Chrome 49, Firefox 54 and Opera 36, this property returns
DOMHighResTimeStamp instead of
DOMTimeStamp .
|
≤12.1
Starting with Chrome 49, Firefox 54 and Opera 36, this property returns
DOMHighResTimeStamp instead of
DOMTimeStamp .
|
1
|
1
Starting with version 49, this property returns
DOMHighResTimeStamp instead of
DOMTimeStamp .
|
18
Starting with Chrome 49, Firefox 54 and Opera 36, this property returns
DOMHighResTimeStamp instead of
DOMTimeStamp .
|
4
Starting with Chrome 49, Firefox 54 and Opera 36, this property returns
DOMHighResTimeStamp instead of
DOMTimeStamp .
|
≤12.1
Starting with Chrome 49, Firefox 54 and Opera 36, this property returns
DOMHighResTimeStamp instead of
DOMTimeStamp .
|
1
|
1.0
Starting with Samsung Internet 5.0, Firefox 54 and Opera 36, this property returns
DOMHighResTimeStamp instead of
DOMTimeStamp .
|
© 2005–2021 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/Event/timeStamp