More information here: http://stackoverflow.com/questions/3088993/webkit-stylewithcss-contenteditable-not-working
> document.execCommand('bold', false, "styleWithCSS", true); That's not how execCommand works. Bold and styleWithCSS are two separate commands that need to be invoked separately: document.execCommand("styleWithCSS", false, "true"); document.execCommand('bold', false, null);