Deprecated
This feature has been removed from the Web standards. Though some browsers may still support it, it is in the process of being dropped. Avoid using it and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

The File.lastModifiedDate read-only property returns the last modified date of the file. Files without a known last modified date returns the current date .

Syntax

var time = instanceOfFile.lastModifiedDate

Value

A Date object.

Example

// fileInput is a HTMLInputElement: <input type="file" multiple id="myfileinput">
var fileInput = document.getElementById("myfileinput");

// files is a FileList object (simliar to NodeList)
var files = fileInput.files;

for (var i = 0; i < files.length; i++) {
  alert(files[i].name + " has a last modified date of " + files[i].lastModifiedDate);
}

Reduced time precision

To offer protection against timing attacks and fingerprinting, the precision of someFile.lastModifiedDate.getTime() 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
someFile.lastModifiedDate.getTime();
// 1519211809934
// 1519211810362
// 1519211811670
// ...


// reduced time precision with `privacy.resistFingerprinting` enabled
someFile.lastModifiedDate.getTime();
// 1519129853500
// 1519129858900
// 1519129864400
// ...

In Firefox, you can also enabled privacy.resistFingerprinting, the precision will be 100ms or the value of privacy.resistFingerprinting.reduceTimerPrecision.microseconds, whichever is larger.

Specifications

Though present in early draft of the File API spec, this property has been removed from it and is now non-standard. Use File.lastModified instead.

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support13 Yes151016 No
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support Yes Yes Yes No No No ?

See also

Document Tags and Contributors

 Last updated by: fscholz,