HTTP Header Checker
Enter any URL. We fetch it and show you every response header the server sent.
What are HTTP headers?
Headers are the metadata a web server sends before the page itself: which server software it runs, what type of content follows, how long browsers may cache it, and which security policies apply. You never see them in normal browsing, but they control a lot of how the web behaves.
Why check headers?
Developers check headers to debug caching problems and confirm security headers like Content-Security-Policy are actually being sent. SEO work sometimes needs the status code and canonical signals. Privacy-minded users check what a site reveals about its stack. If you run a site behind a proxy or CDN, headers show you what the outside world really receives.
Headers worth noticing
Server names the software answering. Content-Type says what kind of data follows. Cache-Control controls caching. Strict-Transport-Security, Content-Security-Policy and X-Frame-Options are security headers, and their absence is worth knowing about. Set-Cookie shows what the site tries to store in your browser.
Frequently asked questions
Is the header checker free?
Yes, free with no signup.
Why do browsers block this but your tool works?
Browsers enforce CORS rules that stop a page from reading another site's headers. Our tool fetches the URL from our server instead, where no such restriction applies, then shows you the result.
Does it download the whole page?
No. It requests headers only, so even huge pages return instantly without wasting bandwidth.
What if a site blocks the check?
Some sites refuse automated requests. You will get a clear error instead of a fake result, which is itself useful information.