HTTP Headers
View all HTTP response headers returned by any URL. Analyze server configuration.
HTTP response headers are the metadata a server returns with every page — describing the server software, caching, content type, cookies, redirects, and security policies. Enter a URL to see the full set of headers it returns, following redirects along the way. It's an essential tool for debugging caching, CORS, redirects, and server configuration.
Frequently asked questions
What are HTTP response headers?
Key-value fields a server sends alongside content to control caching, security, content type, cookies, and more.
What does the Server header reveal?
It often names the web server, such as nginx or Cloudflare. Some operators hide or fake it to reduce fingerprinting.
What is a redirect chain?
The sequence of 3xx responses that forward one URL to another. Long chains slow loads and can leak referrer data.
Why do I see Cloudflare or a CDN in the headers?
Many sites sit behind a CDN, which adds its own headers (like cf-ray) and may mask the origin server.
Which headers matter for security?
Content-Security-Policy, Strict-Transport-Security, and X-Content-Type-Options among others — graded in detail by the Security Headers tool.