Auto start print html page using javascript
Use this script
<script type="text/javascript">
window.onload = function() { window.print(); }
</script>
<body onload="window.print()">
or
window.onload = function() { window.print(); }
The following code must be put at the end of your HTML file so that once the content has loaded, the script will be executed and the window will print.
<script type="text/javascript">
<!--
window.print();
//-->
</script>
Add the following code in your HTML page, and it will show print preview on page load.
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
</head>
<script type="text/javascript">
$(document).ready(function () {
window.print();
});
</script>