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 |
---|---|---|
DOM The definition of 'Event.timeStamp' in that specification. |
Living Standard |
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
timeStamp | Chrome
Full support
49
| Edge Full support 12 | Firefox
Full support
Yes
| IE
Full support
Yes
| Opera
Full support
36
| Safari Full support Yes | WebView Android
Full support
49
| Chrome Android
Full support
49
| Firefox Android
Full support
Yes
| Opera Android
Full support
36
| Safari iOS Full support Yes | Samsung Internet Android
Full support
5.0
|
Legend
- Full support
- Full support
- See implementation notes.
- See implementation notes.