HTTP Header Checker
HTTP response headers control caching, indexing, security, and content negotiation. This tool fetches any URL and shows its full HTTP response status and headers. Useful for diagnosing CDN cache issues, x-robots-tag indexing problems, missing security headers, and CMS fingerprints.
Several response headers directly affect SEO: x-robots-tag controls indexing (overrides meta robots tag), cache-control affects how long CDNs and Google cache content, content-type identifies the MIME type (wrong type = wrong rendering), strict-transport-security signals HTTPS-only enforcement, link header can declare canonical URLs.
Required: content-type, cache-control (set explicitly, do not rely on defaults), strict-transport-security (HSTS, after testing). Recommended: content-security-policy (basic CSP), x-content-type-options: nosniff, x-frame-options or frame-ancestors. Optional: link rel=canonical for non-HTML responses.
Meta robots is a tag inside HTML. x-robots-tag is an HTTP header. Both control crawler behaviour (noindex, nofollow, noarchive). Use header when the response is not HTML (PDF, image) — meta tag does not apply there. Both have the same effect when present.
Browsers send caching headers, cookies, and accept-language that change responses. Our tool sends a clean user-agent and minimal headers. If you see 200 in browser but 403/406 here, the page is bot-blocking (often via Cloudflare or fingerprinting). Test with curl from your own machine if you need exact comparison.
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