ReadableStream: pipeTo() method

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since May 2022.

Note: This feature is available in Web Workers.

The pipeTo() method of the ReadableStream interface pipes the current ReadableStream to a given WritableStream and returns a Promise that fulfills when the piping process completes successfully, or rejects if any errors were encountered.

Piping a stream will generally lock it for the duration of the pipe, preventing other readers from locking it.

Syntax

js
pipeTo(destination)
pipeTo(destination, options)

Parameters

destination

A WritableStream that acts as the final destination for the ReadableStream.

options Optional

The options that should be used when piping to the writable stream. Available options are:

preventClose

If this is set to true, the source ReadableStream closing will no longer cause the destination WritableStream to be closed. The method will return a fulfilled promise once this process completes, unless an error is encountered while closing the destination in which case it will be rejected with that error.

preventAbort

If this is set to true, errors in the source ReadableStream will no longer abort the destination WritableStream. The method will return a promise rejected with the source's error, or with any error that occurs during aborting the destination.

preventCancel

If this is set to true, errors in the destination WritableStream will no longer cancel the source ReadableStream. In this case the method will return a promise rejected with the source's error, or with any error that occurs during canceling the source. In addition, if the destination writable stream starts out closed or closing, the source readable stream will no longer be canceled. In this case the method will return a promise rejected with an error indicating piping to a closed stream failed, or with any error that occurs during canceling the source.

signal

If set to an AbortSignal object, ongoing pipe operations can then be aborted via the corresponding AbortController.

js
// Fetch the original image
fetch("png-logo.png")
  // Retrieve its body as ReadableStream
  .then((response) => response.body)
  .then((body) => body.pipeThrough(new PNGTransformStream()))
  .then((rs) => rs.pipeTo(new FinalDestinationStream()));

The same example, but using await:

js
(async () => {
  // Fetch the original image
  const response = await fetch("png-logo.png");
  // Retrieve its body as ReadableStream
  await response.body
    .pipeThrough(new PNGTransformStream())
    .pipeTo(new FinalDestinationStream());
})();