Background-attachment: fixed

<!DOCTYPE html>
<html lang=en>
<head>
<title></title>
<meta charset=utf-8>
<meta name="viewport" content="width=device-width">
<style>

body {
background-image:url(https://images.pexels.com/photos/1414234/pexels-photo-1414234.jpeg?auto=compress&cs=tinysrgb&dpr=1&w=500);
background-size:100% 100%;
background-attachment:fixed;
 }

</style>
</head>
<body>


<script>

</script>
</body>
</html>