This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The read-only isDirectory property of the FileSystemEntry interface is true if the entry represents a directory (meaning it's a FileSystemDirectoryEntry) and false if it's not.

You can also use isFile to determine if the entry is a file.

You should not assume that any entry which isn't a directory is a file or vice-versa. There are other types of file descriptors on many operating systems. Be sure to use both isDirectory and isFile as needed to ensure that the entry is something you know how to work with.


var isDirectory = FileSystemEntry.isDirectory;


A Boolean indicating whether or not the FileSystemEntry is a directory.


This example shows how this property might be used to determine whether to process the entry as a directory or file. If the entry is neither, an error handler is called with an appropriate message.

if (entry.isDirectory) {
} else if (entry.isFile) {
} else {
  displayErrorMessage("Unsupported file system entry specified.");


Specification Status Comment
File and Directory Entries API
The definition of 'isDirectory' in that specification.
Draft Initial specification.

Browser compatibility

ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
Chrome Full support 8Edge Full support 79Firefox Full support 50IE No support NoOpera No support NoSafari Full support 11.1WebView Android Full support ≤37Chrome Android Full support 18Firefox Android Full support 50Opera Android No support NoSafari iOS Full support 11.3Samsung Internet Android Full support Yes


Full support
Full support
No support
No support
Experimental. Expect behavior to change in the future.
Experimental. Expect behavior to change in the future.

See also