utf8-typed

utf8-typed is a well-tested UTF-8 encoder/decoder written in JavaScript. Unlike many other JavaScript solutions, it is designed to be a proper UTF-8 encoder/decoder: it can encode/decode any scalar Unicode code point values, as per the Encoding Standardstandard.
Feel free to fork if you see possible improvements!

Installation

Via npm:

$ npm install utf8-typed

API

utf8.encode(string)

Encodes any given JavaScript string (string) as UTF-8, returning a UTF-8-encoded Uint8Array. It replaces non-scalar values (i.e. lone surrogates) with U+FFFD replacement characters.

// U+00A9 COPYRIGHT SIGN; see http://codepoints.net/U+00A9
utf8.encode('\xa9');
// → '\xc2\xa9'
// U+10001 LINEAR B SYLLABLE B038 E; see http://codepoints.net/U+10001
utf8.encode('\ud800\udc01');
// → '\xf0\x90\x80\x81'

utf8.decode(byteArray)

Decodes any given UTF-8-encoded Uint8Array (byteArray) as UTF-8, and returns the UTF-8-decoded version of the string. It replaces malformed UTF-8 with U+FFFD replacement characters.

utf8.decode(new Uint8Array([0xc2, 0xa9]));
// → '\xa9'

utf8.decode(new Uint8Array([0xf0, 0x90, 0x80, 0x81]));
// → '\ud800\udc01'
// → U+10001 LINEAR B SYLLABLE B038 E

standard: https://encoding.spec.whatwg.org/#utf-8 npm: https://www.npmjs.com/