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

The WritableStreamDefaultController interface of the the Streams API represents a controller allowing control of a WritableStream's state. When constructing a WritableStream, the underlying sink is given a corresponding WritableStreamDefaultController instance to manipulate.


Creates a new WritableStreamDefaultController object instance.




Causes any future interactions with the associated stream to error.


const writableStream = new WritableStream({
  start(controller) {
    // do stuff with controller

    // error stream if necessary
    controller.error('My error is broken');
  write(chunk, controller) {
  close(controller) {
  abort(err) {


Specification Status Comment
The definition of 'WritableStreamDefaultController' 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 Edge Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 58 (Yes) No support ? 45 ?
Feature Android Webview Chrome for Android Edge Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support 58 58 (Yes) No support ? 45 ?

Document Tags and Contributors

Contributors to this page: chrisdavidmills, abbycar
Last updated by: chrisdavidmills,