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Chardet is a character detection module written in pure JavaScript (TypeScript). Module uses occurrence analysis to determine the most probable encoding.

  • Packed size is only 22 KB
  • Works in all environments: Node / Browser / Native
  • Works on all platforms: Linux / Mac / Windows
  • No dependencies
  • No native code / bindings
  • 100% written in TypeScript
  • Extensive code coverage


npm i chardet


To return the encoding with the highest confidence:

import chardet from 'chardet';

const encoding = chardet.detect(Buffer.from('hello there!'));
// or
const encoding = await chardet.detectFile('/path/to/file');
// or
const encoding = chardet.detectFileSync('/path/to/file');

To return the full list of possible encodings use analyse method.

import chardet from 'chardet';
chardet.analyse(Buffer.from('hello there!'));

Returned value is an array of objects sorted by confidence value in descending order

  { confidence: 90, name: 'UTF-8' },
  { confidence: 20, name: 'windows-1252', lang: 'fr' },

In browser, you can use Uint8Array instead of the Buffer:

import chardet from 'chardet';
chardet.analyse(new Uint8Array([0x68, 0x65, 0x6c, 0x6c, 0x6f]));

Working with large data sets

Sometimes, when data set is huge and you want to optimize performance (with a tradeoff of less accuracy), you can sample only the first N bytes of the buffer:

  .detectFile('/path/to/file', { sampleSize: 32 })
  .then((encoding) => console.log(encoding));

You can also specify where to begin reading from in the buffer:

  .detectFile('/path/to/file', { sampleSize: 32, offset: 128 })
  .then((encoding) => console.log(encoding));

Supported Encodings:

  • UTF-8
  • UTF-16 LE
  • UTF-16 BE
  • UTF-32 LE
  • UTF-32 BE
  • ISO-2022-JP
  • ISO-2022-KR
  • ISO-2022-CN
  • Shift_JIS
  • Big5
  • EUC-JP
  • EUC-KR
  • GB18030
  • ISO-8859-1
  • ISO-8859-2
  • ISO-8859-5
  • ISO-8859-6
  • ISO-8859-7
  • ISO-8859-8
  • ISO-8859-9
  • windows-1250
  • windows-1251
  • windows-1252
  • windows-1253
  • windows-1254
  • windows-1255
  • windows-1256
  • KOI8-R

Currently only these encodings are supported.


Yes. Type definitions are included.