Window: requestFileSystem() method

Deprecated: This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. 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.

Non-standard: 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 non-standard Window method requestFileSystem() method is a Google Chrome-specific method which lets a website or app gain access to a sandboxed file system for its own use. The returned FileSystem is then available for use with the other file system APIs.

Note: This method is prefixed with webkit in all browsers that implement it.


requestFileSystem(type, size, successCallback)
requestFileSystem(type, size, successCallback, errorCallback)



The type of storage to request. Specify Window.TEMPORARY if it's acceptable for the browser to delete the files at its own discretion, such as if storage space runs low, or Window.PERSISTENT if you need the files to remain in place unless the user or the website or app explicitly permit it. Persistent storage requires that the user grant the site quota.


The amount of storage space you wish to have allocated for your app's use.


A function which is invoked when the file system has been successfully obtained. The callback receives a single parameter: a FileSystem object representing the file system the app has permission to use.

errorCallback Optional

An optional parameter specifying a function which is called if an error occurs while attempting to obtain the file system, or if the user denies permission to create or access the file system. The callback receives as input a single parameter: a FileError object describing the error.

Return value

None (undefined).


As this method was removed from the File and Directory Entries API proposal, it has no official W3C or WHATWG specification. It is no longer on track to become a standard.

Browser compatibility

BCD tables only load in the browser

See also