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.

Note: The three non-standard interfaces IDBMutableFile, IDBFileHandle, and IDBFileRequest are disabled by default. Consider using the File and Directory Entries API instead.

The IDBMutableFile interface provides access in read or write mode to a file, dealing with all the necessary locks.

As IDBMutableFile objects are bound to a fake file system built using IndexedDB, such an object is created using the IDBDatabase.createMutableFile() method.

Instance properties Read only

The name of the handled file.

IDBMutableFile.type Read only

The MIME type of the handled file.

Instance methods

Returns a IDBFileHandle object to read or write the associated file safely.



Fired when the handled file is aborted.


Fired when something goes wrong.


This feature is not part of any current specification. It is no longer on track to become a standard.

Browser compatibility

This interface is not supported by any current browser. From Firefox 102 it is behind the preference dom.fileHandle.enabled.

See also