Nerdy Programmers Mingling

    TypeScript icon, indicating that this package has built-in type declarations

    0.6.3 • Public • Published

    iconv-lite: Pure JS character encoding conversion

    • No need for native code compilation. Quick to install, works on Windows and in sandboxed environments like Cloud9.
    • Used in popular projects like Express.js (body_parser), Grunt, Nodemailer, Yeoman and others.
    • Faster than node-iconv (see below for performance comparison).
    • Intuitive encode/decode API, including Streaming support.
    • In-browser usage via browserify or webpack (~180kb gzip compressed with Buffer shim included).
    • Typescript type definition file included.
    • React Native is supported (need to install stream module to enable Streaming API).
    • License: MIT.

    NPM Stats
    Build Status npm npm downloads npm bundle size


    Basic API

    var iconv = require('iconv-lite');
    // Convert from an encoded buffer to a js string.
    str = iconv.decode(Buffer.from([0x68, 0x65, 0x6c, 0x6c, 0x6f]), 'win1251');
    // Convert from a js string to an encoded buffer.
    buf = iconv.encode("Sample input string", 'win1251');
    // Check if encoding is supported

    Streaming API

    // Decode stream (from binary data stream to js strings)
    http.createServer(function(req, res) {
        var converterStream = iconv.decodeStream('win1251');
        converterStream.on('data', function(str) {
            console.log(str); // Do something with decoded strings, chunk-by-chunk.
    // Convert encoding streaming example
    // Sugar: all encode/decode streams have .collect(cb) method to accumulate data.
    http.createServer(function(req, res) {
        req.pipe(iconv.decodeStream('win1251')).collect(function(err, body) {
            assert(typeof body == 'string');
            console.log(body); // full request body string

    Supported encodings

    • All node.js native encodings: utf8, ucs2 / utf16-le, ascii, binary, base64, hex.
    • Additional unicode encodings: utf16, utf16-be, utf-7, utf-7-imap, utf32, utf32-le, and utf32-be.
    • All widespread singlebyte encodings: Windows 125x family, ISO-8859 family, IBM/DOS codepages, Macintosh family, KOI8 family, all others supported by iconv library. Aliases like 'latin1', 'us-ascii' also supported.
    • All widespread multibyte encodings: CP932, CP936, CP949, CP950, GB2312, GBK, GB18030, Big5, Shift_JIS, EUC-JP.

    See all supported encodings on wiki.

    Most singlebyte encodings are generated automatically from node-iconv. Thank you Ben Noordhuis and libiconv authors!

    Multibyte encodings are generated from mappings and WHATWG Encoding Standard mappings. Thank you, respective authors!

    Encoding/decoding speed

    Comparison with node-iconv module (1000x256kb, on MacBook Pro, Core i5/2.6 GHz, Node v0.12.0). Note: your results may vary, so please always check on your hardware.

    operation             iconv@2.1.4   iconv-lite@0.4.7
    encode('win1251')     ~96 Mb/s      ~320 Mb/s
    decode('win1251')     ~95 Mb/s      ~246 Mb/s

    BOM handling

    • Decoding: BOM is stripped by default, unless overridden by passing stripBOM: false in options (f.ex. iconv.decode(buf, enc, {stripBOM: false})). A callback might also be given as a stripBOM parameter - it'll be called if BOM character was actually found.
    • If you want to detect UTF-8 BOM when decoding other encodings, use node-autodetect-decoder-stream module.
    • Encoding: No BOM added, unless overridden by addBOM: true option.

    UTF-16 Encodings

    This library supports UTF-16LE, UTF-16BE and UTF-16 encodings. First two are straightforward, but UTF-16 is trying to be smart about endianness in the following ways:

    • Decoding: uses BOM and 'spaces heuristic' to determine input endianness. Default is UTF-16LE, but can be overridden with defaultEncoding: 'utf-16be' option. Strips BOM unless stripBOM: false.
    • Encoding: uses UTF-16LE and writes BOM by default. Use addBOM: false to override.

    UTF-32 Encodings

    This library supports UTF-32LE, UTF-32BE and UTF-32 encodings. Like the UTF-16 encoding above, UTF-32 defaults to UTF-32LE, but uses BOM and 'spaces heuristics' to determine input endianness.

    • The default of UTF-32LE can be overridden with the defaultEncoding: 'utf-32be' option. Strips BOM unless stripBOM: false.
    • Encoding: uses UTF-32LE and writes BOM by default. Use addBOM: false to override. (defaultEncoding: 'utf-32be' can also be used here to change encoding.)

    Other notes

    When decoding, be sure to supply a Buffer to decode() method, otherwise bad things usually happen.
    Untranslatable characters are set to � or ?. No transliteration is currently supported.
    Node versions 0.10.31 and 0.11.13 are buggy, don't use them (see #65, #77).


    $ git clone
    $ cd iconv-lite
    $ npm install
    $ npm test
    $ # To view performance:
    $ node test/performance.js
    $ # To view test coverage:
    $ npm run coverage
    $ open coverage/lcov-report/index.html


    npm i iconv-lite

    DownloadsWeekly Downloads






    Unpacked Size

    349 kB

    Total Files


    Last publish


    • ashtuchkin