HTTP headers lookup
What the HTTP headers lookup shows
Submit a URL and inspect the response headers from a normal GET through this platform's fetch path. You will see protocol-level facts such as cache-control, content-type, redirect targets (location), transport negotiation hints, security policies (strict-transport-security, content-security-policy, x-frame-options), and bot directives (x-robots-tag). Headers explain why a CDN caches aggressively, why a frame refuses to embed, or why a crawler sees noindex even when HTML looks fine.
When to use it
Use it when SEO tools disagree about indexing, when browsers loop through redirects, when assets never refresh despite deploys, or when security auditors ask for proof of HSTS preload readiness. Pair with Meta tags checker because robots directives can live in headers instead of <meta> tags. Pair with URL redirect checker when chains get long.
Worked example
Marketing says the PDF moved. Headers lookup shows 301 with cache-control: max-age=86400 at the CDN edge while origin sends 302. You now know browsers might reuse the first hop decision for a day. Purge the CDN or shorten TTL before chasing application bugs.
Frequently asked questions
Is this identical to DevTools Network?
Similar intent. DevTools runs on your machine with your cookies; this tool runs remotely with different TLS fingerprints and no logged-in session unless you pass credentials (do not paste secrets).
Why is Content-Encoding odd?
Proxies may decompress bodies but preserve encoding labels. Compare byte sizes with curl if you need raw wire proof.
Can I see HTTP/2 specifics?
Hop-by-hop frames are not listed here. Use HTTP/2 Checker for protocol family confirmation plus this tool for semantic headers.
Does header order matter?
HTTP/2 multiplexes differently than HTTP/1.1, but security scanners still read semantic values regardless of order.