This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The ReadableStreamDefaultReader interface of the Streams API represents a BYOB ("bring your own buffer") reader that can be used to read stream data supplied by the developer (e.g. a custom ReadableStream.ReadableStream() constructor).


Creates and returns a ReadableStreamBYOBReader() object instance.


Allows you to write code that responds to an end to the streaming process. Returns a promise that fulfills if the stream becomes closed or the reader's lock is released, or rejects if the stream errors.


Cancels the stream, signaling a loss of interest in the stream by a consumer. The supplied reason argument will be given to the underlying source, which may or may not use it.
Returns a promise providing access to the next chunk in the stream's internal queue.
Releases the reader's lock on the stream.




Specification Status Comment
The definition of 'ReadableStreamBYOBReader' in that specification.
Living Standard Initial definition

Browser Compatibility

We're converting our compatibility data into a machine-readable JSON format. This compatibility table still uses the old format, because we haven't yet converted the data it contains. Find out how you can help!

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support

No support

No support No support

No support

No support
Feature Android Webview Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support No support No support No support No support No support No support


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Contributors to this page: chrisdavidmills, aardgoose, fscholz
Last updated by: chrisdavidmills,