<link rel="shortcut icon" type="image/png" href="img/apple-touch-icon.png"> code example

Example: html favicon.ico

<! -- For .ico files -->
<link rel="shortcut icon" href="favicon.ico" type="image/x-icon">

<! -- For .jpg/.gif/.png files -->
<link rel="icon" type="image/gif/png" href="favicon.png">