TextDecoder and TextEncoder in Javascript?

TextEncoder is used to convert a given string to utf-8 standard. It retunes an Uint8Array from the string.

TextDecoder is used to covert a stream of bytes into a stream of code points. It can decode UTF-8 , ISO-8859-2, KOI8-R, GBK etc.

Following is the code for TextDecoder and TextEncoder in JavaScript −


 Live Demo

<!DOCTYPE html>
<html lang="en">
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
   body {
      font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
   .result,.sample {
      font-size: 18px;
      font-weight: 500;
      color: rebeccapurple;
   .result {
      color: red;
<h1>TextDecoder and TextEncoder in Javascript</h1>
<div class="sample"></div>
<button class="Btn">ENCODE STRING</button>
<div class="result"></div>
<h3>Click on the above button to encode the above string</h3>
<div class="sample"></div>
<button class="Btn">Decode STRING</button>
<div class="result"></div>
<h3>Click on the above button to decode the above string</h3>
   let BtnEle = document.querySelectorAll(".Btn");
   let sampleEle = document.querySelectorAll(".sample");
   let resEle = document.querySelectorAll(".result");
   let str = "Hello world";
   let str1 = new Uint8Array([119, 111, 114, 108, 100]);
   sampleEle[0].innerHTML = str;
   sampleEle[1].innerHTML = str1;
   BtnEle[0].addEventListener("click", () => {
      let textEncoder = new TextEncoder();
      resEle[0].innerHTML += "Encoded String = " + textEncoder.encode(str) + "<br>";
   BtnEle[1].addEventListener("click", () => {
      let textDecoder = new TextDecoder();
      resEle[1].innerHTML += "Decoded String = " + textDecoder.decode(str1) + "<br>";


The above code will produce the following output −

On clicking the ‘ENCODE STRING’ button −

On clicking the ‘Decode STRING’ button −

Updated on: 17-Jul-2020


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