Chardet is a character detection module for NodeJS written in pure Javascript. Module is based on ICU project http://site.icu-project.org/, which uses character occurency analysis to determine the most probable encoding.
npm i chardet
To return the encoding with the highest confidence:
var chardet = require('chardet');
chardet.detect(Buffer.alloc('hello there!'));
// or
chardet.detectFile('/path/to/file', function(err, encoding) {});
// or
chardet.detectFileSync('/path/to/file');
To return the full list of possible encodings:
var chardet = require('chardet');
chardet.detectAll(Buffer.alloc('hello there!'));
// or
chardet.detectFileAll('/path/to/file', function(err, encoding) {});
// or
chardet.detectFileAllSync('/path/to/file');
//Returned value is an array of objects sorted by confidence value in decending order
//e.g. [{ confidence: 90, name: 'UTF-8'}, {confidence: 20, name: 'windows-1252', lang: 'fr'}]
Sometimes, when data set is huge and you want to optimize performace (in tradeoff of less accuracy), you can sample only first N bytes of the buffer:
chardet.detectFile('/path/to/file', { sampleSize: 32 }, function(err, encoding) {});
Currently only these encodings are supported, more will be added soon.