HTTP Headers Lookup
See exactly what a server sends back — and which security headers are missing.
- Online lookup — sends only the address you type
- 100% free
- No sign-up
How to check HTTP headers
- Paste a URL.
- Choose the user agent, method and whether to follow redirects.
- Read the chain, grade, cookies and all headers; share the link.
About HTTP Headers Lookup
See the HTTP response headers of any URL.
It works in your browser for speed and privacy, remembers your settings on this device, and every result can be copied, downloaded or shared.
Good for
- SEO redirect audits
- Security header hardening
- Debugging caching and CDNs
Tip: Aim for a single 301 from http:// or www to your final URL — every extra hop costs time.
Frequently asked questions
How is the security grade worked out?
It checks six headers that protect visitors: Strict-Transport-Security, Content-Security-Policy, X-Frame-Options (or CSP frame-ancestors), X-Content-Type-Options, Referrer-Policy and Permissions-Policy. All six give an A; A+ also needs HSTS preload.
Can I see redirects?
Yes — every hop (301, 302, 307, 308) is listed with its status, address and time, so you can spot redirect chains and loops that slow pages and waste SEO.
Can I test as Googlebot or a phone?
Yes — pick the user agent to see what search engines or mobile browsers get.
Why is my cookie flagged?
Cookies should have Secure, HttpOnly and SameSite where possible, to stop theft over HTTP, by scripts, or in cross-site requests.
How is the URL checked?
Our server requests the URL for you, because browsers hide most response headers. Results aren't saved.