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 web site 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.

Even compared to the rest of the File and Directory Entries API, requestFileSystem() is especially non-standard; only Chrome implements it, and all other browser makers have decided that they will not implement it. It has even been removed from the proposed specification. Do not use this method!


This method is prefixed with webkit in all browsers that implement it (that is, Google Chrome).

window.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 web site 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




Specification Status Comment
File and Directory Entries API Draft Draft of proposed API

This API has no official W3C or WHATWG specification.

Browser compatibility

BCD tables only load in the browser

See also