TextDecoderStream: TextDecoderStream() constructor

Baseline Widely available

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

Note: This feature is available in Web Workers.

The TextDecoderStream() constructor creates a new TextDecoderStream object which is used to convert a stream of text in a binary encoding into strings.

Syntax

js
new TextDecoderStream(label)
new TextDecoderStream(label, options)

Parameters

label

A string defaulting to utf-8. This may be any valid label.

options Optional

An object with the following properties:

fatal Optional

A boolean value indicating if the TextDecoder.decode() method must throw a TypeError when decoding invalid data. It defaults to false, which means that the decoder will substitute malformed data with a replacement character.

ignoreBOM Optional

A boolean value indicating whether the byte order mark will be included in the output or skipped over. It defaults to false, which means that the byte order mark will be skipped over when decoding and will not be included in the decoded text.

Exceptions

RangeError

Thrown if the value of label is unknown, or is one of the values leading to a 'replacement' decoding algorithm ("iso-2022-cn" or "iso-2022-cn-ext").

Examples

The following example demonstrates how to decode binary data retrieved from a fetch() call. The data will be interpreted as UTF-8, as no label has been passed.

js
const response = await fetch("https://example.com");
const stream = response.body.pipeThrough(new TextDecoderStream());

Specifications

Specification

Encoding
# ref-for-dom-textdecoderstream①

Browser compatibility

Enable JavaScript to view this browser compatibility table.

Help improve MDN

Was this page helpful to you?

Yes No

Learn how to contribute

This page was last modified on Jun 23, 2025 by MDN contributors.

View this page on GitHub • Report a problem with this content