HTTP Header Checker

Enter a URL to see exactly what the server sends back: every response header, each hop in the redirect chain, and a timing breakdown showing where the milliseconds actually go — DNS, connection, TLS handshake and time to first byte.

Requests are made from our server, so you see the response a fresh visitor gets rather than one shaped by your browser cache, extensions or cookies.

How it works

Every HTTP response carries headers describing how it should be handled. Most are invisible in normal browsing, yet they control caching, security, compression and content negotiation — and when a site misbehaves, the answer is usually sitting in one of them.

The headers worth checking first:

• cache-control and etag — whether responses are cacheable, and for how long. A missing cache-control on static assets is one of the most common and easily fixed performance problems.
• content-encoding — should be gzip or br for text. Its absence means you are shipping uncompressed HTML, CSS and JavaScript.
• strict-transport-security — tells browsers to use HTTPS for this domain in future, closing the window where a first plain-HTTP request can be intercepted.
• server and x-powered-by — often disclose exact software versions. Neither is required, and removing them denies attackers a free inventory of what you run.

The redirect chain matters more than it looks. Each hop is a full round trip — DNS, TCP, TLS, request, response — so a chain of three redirects can add several hundred milliseconds before the real page starts loading. The classic accidental chain is http://example.com → https://example.com → https://www.example.com, which costs two round trips where one would do.

The timing breakdown separates the phases so you can tell where a slow response actually originates. High DNS time points at your DNS provider; high connect or TLS time points at network distance or handshake configuration; high time-to-first-byte with everything else fast points squarely at server-side processing.

Frequently asked questions