add image as icon html
<!DOCTYPE html>
<html lang="en">
<head>
<title>Document</title>
<!--
make sure your icon (proposed image)is in the same folder with your html file,
and change "favicon.ico" into your image name
-->
<link rel="shortcut icon" href="favicon.ico" type="image/x-icon">
</head>
<body>
</body>
</html>