TextDecoder

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since ⁨January 2020⁩.

Note: This feature is available in Web Workers.

The TextDecoder interface represents a decoder for a specific text encoding, such as UTF-8, ISO-8859-2, or GBK. A decoder takes an array of bytes as input and returns a JavaScript string.

Constructor

TextDecoder(): Creates and returns a new TextDecoder.

Instance properties

The TextDecoder interface doesn't inherit any properties.

TextDecoder.encoding Read only: A string containing the name of the character encoding system that this TextDecoder will use.
TextDecoder.fatal Read only: A boolean indicating whether the error mode is fatal.
TextDecoder.ignoreBOM Read only: A boolean indicating whether the byte order mark is ignored.

Instance methods

The TextDecoder interface doesn't inherit any methods.

TextDecoder.decode(): Decodes the given bytes into a JavaScript string and returns it.

Examples

Decoding UTF-8 text

This example shows how to decode the UTF-8 encoding of the character "𠮷".

html

<button id="decode">Decode</button> <button id="reset">Reset</button> <div id="output"></div>

div { margin: 1rem 0; }

const utf8decoder = new TextDecoder(); // default 'utf-8' const encodedText = new Uint8Array([240, 160, 174, 183]); const output = document.querySelector("#output"); const decodeButton = document.querySelector("#decode"); decodeButton.addEventListener("click", () => { output.textContent = utf8decoder.decode(encodedText); }); const resetButton = document.querySelector("#reset"); resetButton.addEventListener("click", () => { window.location.reload(); });

Decoding non-UTF8 text

In this example, we decode the Russian text "Привет, мир!", which means "Hello, world." In our TextDecoder() constructor, we specify the Windows-1251 character encoding.

html

<button id="decode">Decode</button> <button id="reset">Reset</button> <div id="decoded"></div>

div { margin: 1rem 0; }

const win1251decoder = new TextDecoder("windows-1251"); const encodedText = new Uint8Array([ 207, 240, 232, 226, 229, 242, 44, 32, 236, 232, 240, 33, ]); const decoded = document.querySelector("#decoded"); const decodeButton = document.querySelector("#decode"); decodeButton.addEventListener("click", () => { decoded.textContent = win1251decoder.decode(encodedText); }); const resetButton = document.querySelector("#reset"); resetButton.addEventListener("click", () => { window.location.reload(); });

Specifications

Specification
Encoding # interface-textdecoder

Browser compatibility

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This page was last modified on ⁨Jun 28, 2025⁩ by MDN contributors.

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