chardet

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

Installation

npm i chardet

Usage

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:

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

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

chardet
  .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.

TypeScript?

Yes. Type definitions are included.

References

• ICU project http://site.icu-project.org/