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 readAsText() method of the IDBFileHandle interface reads the content of the associated file and provide the result of that reading as a string. In many ways, it performs like the FileReader.readAsText() method.

The reading operation starts at the position given by the location property.

Note: The three interfaces IDBMutableFile, IDBFileHandle, and IDBFileRequest are deprecated and only implemented for backward compatibility in Firefox. Do not use them anymore: consider using the File and Directory Entries API instead.


readAsText(size, encoding)



A number representing the number of bytes to read in the file.

encoding Optional

A string indicating the encoding to use for the returned data. By default, UTF-8 is assumed if this parameter is not specified.

Return value

An IDBFileRequest object to handle the success or failure of the operation. In case of success, the request's result is a string representing the data that have been read.


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

Browser compatibility

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See also