This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.

This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.

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.
Editor's Draft Initial specification.

This API has no official W3C or WHATWG specification.

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 13 webkit 50 (50) No support No support No support
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Phone Opera Mobile Safari Mobile
Basic support No support 0.16 webkit 50.0 (50) No support No support No support

See also


© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.

API File and Directory Entries API File System API Files FileSystemEntry isDirectory Non-Standard Non-standard offline Offline Property Reference