Viewing Returned Headers

Some browsers return a lot of header information when a web page is requested. Some only a few lines.

The header response includes the response code — 200, 404 not found, 301 or 302 redirects, server errors, forbidden, …  (Wikipedia has list). The header response contains any cookies the web page is setting. If there is cache control, the header response describes it. Often, there is additional information such as server type and content length.

The script below publishes the headers of any valid URL on the internet. Use it when you are curious or when you need specific information.

<?php
if(isset($_GET['url']))
{
   $ch=curl_init();
   curl_setopt($ch,CURLOPT_URL,$_GET['url']);
   curl_setopt($ch,CURLOPT_HEADER,true);
   curl_setopt($ch,CURLOPT_RETURNTRANSFER,true);
   $content=curl_exec($ch);
	list($header,$content) = preg_split('/\r\n\r\n/',$content,2);
	curl_close($ch);
   echo $header;
}
?>

Save the above source code as getheaders.php or other *.php file name.

Use the script by typing it's URL into your browser's address bar followed with ?url=[URL]

Replace [URL] with the URL to get the header response from. Example:

https://example.com/getheaders.php?url=https://www.willmaster.com

The following header lines are for the example.com home web page. To see the headers for this willmaster.com web page, tap on this link. The page will reload and display this page's header response.

HTTP/2 200 
content-type: text/html
etag: "84238dfc8092e5d9c0dac8ef93371a07:1736799080.121134"
last-modified: Mon, 13 Jan 2025 20:11:20 GMT
cache-control: max-age=717
date: Thu, 01 May 2025 03:32:19 GMT
alt-svc: h3=":443"; ma=93600,h3-29=":443"; ma=93600,quic=":443"; ma=93600; v="43"
content-length: 1256

(This tip first appeared in Possibilities newsletter.)

Will Bontrager