pillarjs/iconv-lite

iconv-lite: Pure JS character encoding conversion

• No need for native code compilation. Quick to install, works on Windows, Web, and in sandboxed environments.
• 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).

Usage

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
iconv.encodingExists("us-ascii")

Streaming API

// Decode stream (from binary data stream to js strings)
http.createServer(function(req, res) {
    var converterStream = iconv.decodeStream('win1251');
    req.pipe(converterStream);

    converterStream.on('data', function(str) {
        console.log(str); // Do something with decoded strings, chunk-by-chunk.
    });
});

// Convert encoding streaming example
fs.createReadStream('file-in-win1251.txt')
    .pipe(iconv.decodeStream('win1251'))
    .pipe(iconv.encodeStream('ucs2'))
    .pipe(fs.createWriteStream('file-in-ucs2.txt'));

// 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 Unicode.org 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             [email protected]   [email protected]
----------------------------------------------------------
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.)
• Decoding is strict (per the Unicode Standard): a code unit that is a surrogate code point (U+D800–U+DFFF), is above U+10FFFF, or is a truncated trailing code unit is replaced with �. Pass { fatal: true } to throw on such input instead.
• Encoding replaces a lone (unpaired) surrogate in the input with � so the output is always valid UTF-32.

UTF-7 Encodings

This library supports UTF-7 (RFC 2152) and UTF-7-IMAP / Modified UTF-7 (RFC 3501).

• Encoding: for UTF-7, the optional "Set O" punctuation is left as direct ASCII (per RFC 2152), so output stays compact.
• Decoding follows RFC 2152: ill-formed input — an incomplete code unit, non-zero Base64 padding bits, a shift-in not followed by Base64 or "-", or a non-ASCII byte outside a shifted run — is replaced with �. Lone surrogates pass through as their raw 16-bit code units.
• The fatal decode option is not supported (RFC 2152 doesn't define it); decoding is always lenient (replacement with �).

UTF-7 is designed for short, 7-bit-safe strings (mail headers, IMAP mailbox names) and is best used that way. It is not recommended for large or bulk text, where the native utf8/utf16 encodings are faster.

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).

Testing

git clone [email protected]:ashtuchkin/iconv-lite.git
cd iconv-lite
npm install
npm test
    
# To view performance:
npm run test:performance

# To view test coverage: 
npm run test:cov
open coverage/index.html