The timeStamp
read-only property of the Event
interface returns the time (in milliseconds) at which the event was created.
Note: This property only works if the event system supports it for the particular event.
Syntax
time = event.timeStamp;
Value
This value is the number of milliseconds elapsed from the beginning of the current document's lifetime till the event was created.
In newer implementations, the value is a DOMHighResTimeStamp
accurate to 5 microseconds (0.005 ms). In older implementations, the value is a DOMTimeStamp
, accurate to a millisecond.
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 20us in Firefox 59; in 60 it will be 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 | Status | Comment |
---|---|---|
DOMThe definition of 'Event.timeStamp' in that specification. | Living Standard |
Browser compatibility
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Update compatibility data on GitHub
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
timeStamp
|
Chrome Full support 49 Full support 49 Notes' Starting with Chrome 49, Firefox 54 and Opera 36, this property returns |
Edge
Full support 12 |
Firefox Full support Yes Full support Yes Notes' Starting with Chrome 49, Firefox 54 and Opera 36, this property returns |
IE Full support Yes Full support Yes Notes' Starting with Chrome 49, Firefox 54 and Opera 36, this property returns |
Opera Full support 36 Full support 36 Notes' Starting with Chrome 49, Firefox 54 and Opera 36, this property returns |
Safari
Full support Yes |
WebView Android Full support 49 Full support 49 Notes' Starting with version 49, this property returns |
Chrome Android Full support 49 Full support 49 Notes' Starting with Chrome 49, Firefox 54 and Opera 36, this property returns |
Firefox Android Full support Yes Full support Yes Notes' Starting with Chrome 49, Firefox 54 and Opera 36, this property returns |
Opera Android Full support 36 Full support 36 Notes' Starting with Chrome 49, Firefox 54 and Opera 36, this property returns |
Safari iOS
Full support Yes |
Samsung Internet Android Full support 5.0 Full support 5.0 Notes' Starting with Samsung Internet 5.0, Firefox 54 and Opera 36, this property returns |
Legend
- Full support
- Full support
- See implementation notes.'
- See implementation notes.
Event.timeStamp by Mozilla Contributors is licensed under CC-BY-SA 2.5.