How does the HTTP header viewer work?

Our server sends a HEAD request for the URL you enter, which asks for the response headers without the file itself. It shows the headers exactly as the website sent them back, including the status line (for example HTTP/2 200).

The request says it accepts compressed data, as browsers do, so the headers are close to what a browser would get.

Redirects aren't followed: if the URL redirects, you see the redirect itself (such as 301 and its Location header), which is often what you want to check.

Only public http:// and https:// addresses can be checked. We stop waiting after 15 seconds, and each visitor can run up to 20 checks a minute. A few servers answer HEAD requests differently from normal page requests.

Last updated: September 29, 2026 (12:47 AM GMT)