HTML to add the title bar icon

<link rel="icon" href="images/logo.icon" type="image/x-icon">

You can also use "shortcut icon"

short icon, the icon in the left trait browser address bar displays, usually size is 16 * 16, the suffix icon;

icon refers to the icon format PNG | GIF | JPEG, size is generally 16 * 16, 24 * 24, 36 * 36;