manual conversion vs TextEncoder

benchmark.js

var tries   = 100000,
    encoder = new TextEncoder('utf-8'),
    example = 'I♥☢𝄢. I\'m a ☢ ☃ that plays 𝄢 guitar and spea̧͈͖ks Ar̽̾̈́͒͑ ̶̧̨̱̹̭̯ͧ̾ͬC̷̙̲̝͖ͭ̏ͥͮ͟Oͮ͏̮̪̝͍M̲̖͊̒ͪͩͬ̚̚͜!',
    time, index;

function utf8ToBinaryString ( str ) {
    var escstr = encodeURIComponent(str);
    // replaces any uri escape sequence, such as %0A,
    // with binary escape, such as 0x0A
    var binstr = escstr.replace(/%([0-9A-F]{2})/g, function ( match, p1 ) {
        return String.fromCharCode(parseInt(p1, 16));
    });

    return binstr;
}

function binaryStringToBuffer ( binstr ) {
    var buf;

    if ( 'undefined' !== typeof Uint8Array ) {
        buf = new Uint8Array(binstr.length);
    } else {
        buf = [];
    }

    Array.prototype.forEach.call(binstr, function ( ch, i ) {
        buf[i] = ch.charCodeAt(0);
    });

    return buf;
}

function utf8ToBuffer ( str ) {
    var binstr = utf8ToBinaryString(str);
    var buf = binaryStringToBuffer(binstr);
    return buf;
}

console.log('match conversions: %s', encoder.encode(example).join(',') === utf8ToBuffer(example).join(','));

time = Date.now();

for ( index = 0; index < tries; index++ ) {
    encoder.encode(example);
}

console.log('TextEncoder is ready in %sms', Date.now() - time);


time = Date.now();

for ( index = 0; index < tries; index++ ) {
    utf8ToBuffer(example);
}

console.log('manual conversion is ready in %sms', Date.now() - time);