How to convert text to binary code in JavaScript?

Question

Text to Binary Code

I want JavaScript to translate text in a textarea into binary code.

For example, if a user types in "TEST

Answer 1

The other answers will work for most cases. But it's worth noting that charCodeAt() and related don't work with UTF-8 strings (that is, they throw errors if there are any characters outside the standard ASCII range). Here's a workaround.

// UTF-8 to binary
var utf8ToBin = function( s ){
    s = unescape( encodeURIComponent( s ) );
    var chr, i = 0, l = s.length, out = '';
    for( ; i < l; i ++ ){
        chr = s.charCodeAt( i ).toString( 2 );
        while( chr.length % 8 != 0 ){ chr = '0' + chr; }
        out += chr;
    }
    return out;
};

// Binary to UTF-8
var binToUtf8 = function( s ){
    var i = 0, l = s.length, chr, out = '';
    for( ; i < l; i += 8 ){
        chr = parseInt( s.substr( i, 8 ), 2 ).toString( 16 );
        out += '%' + ( ( chr.length % 2 == 0 ) ? chr : '0' + chr );
    }
    return decodeURIComponent( out );
};

The escape/unescape() functions are deprecated. If you need polyfills for them, you can check out the more comprehensive UTF-8 encoding example found here: http://jsfiddle.net/47zwb41o