Encode URI (edit)
var arr = []; for(var i=0;i<256;i++) { var char=String.fromCharCode(i); if(encodeURI(char)!==encodeURIComponent(char)) { arr.push({ character:char, encodeURI:encodeURI(char), encodeURIComponent:encodeURIComponent(char) }); } } console.table(arr);