<!DOCTYPE html>
<html>
<body>
<p>The getAllResponseHeaders() function returns the header information of a resource, like length, server-type, content-type, last-modified, etc.</p>
<button onclick="loadDoc()">Get header information</button>
<p id="demo"></p>
<script>
function loadDoc() {
var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function() {
if (xhttp.readyState == 4 && xhttp.status == 200) {
document.getElementById("demo").innerHTML = xhttp.getAllResponseHeaders();
}
};
xhttp.open("GET", "ajax_info.txt", true);
xhttp.send();
}
</script>
</body>
</html>