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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 append method is used to write some data at the end of the file.

The write operation is performed at the end of the file, regardless of the LockedFile.location value, and actually sets this value to null.


var request = instanceOfLockedFile.append(data);


The data to write into the file. It can be a string or an ArrayBuffer.


A FileRequest object to handle the success or failure of the operation.


Specification Status Comment
FileSystem API Editor's Draft Draft proposal

See also

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 Contributors to this page: fscholz, kscarfone, Jeremie
 Last updated by: fscholz,