<!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="loadXMLDoc('xmlhttp_info.txt')">Get header information</button>
<p id="demo"></p>
<script>
function loadXMLDoc(url) {
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange=function() {
if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
document.getElementById("demo").innerHTML =
xmlhttp.getAllResponseHeaders();
}
};
xmlhttp.open("GET", url, true);
xmlhttp.send();
}
</script>
</body>
</html>