usefulweb.site HTTP Technology Explorer

Internet infrastructure explorers

HTTP Technology Explorer

Headers, compression, caching, HTTP/2-3 hints, redirects, security and tech stack for a URL.

Output of curl -sIL or the browser's raw response headers. Several blocks are read as a redirect chain.

Try an example: WordPress shop behind nginx (pasted)

How it works

Fetches a public URL (or analyses pasted raw response headers and HTML) and explains what the response reveals: redirect target and HTTPS upgrade, HTTP/2 and HTTP/3 advertisement (Alt-Svc), compression, caching (Cache-Control, ETag, Last-Modified, Age, Vary), security headers, and server, framework, CMS and analytics fingerprints with a confidence level for each.

  • Live mode: one GET of the URL through the platform's SSRF-guarded fetcher (redirects followed and re-validated, ports 80/443 only, body capped at 512 KiB), plus a small GET of the http:// variant to see whether plain HTTP is upgraded to HTTPS.
  • The fetcher speaks HTTP/1.1, so HTTP/2 and HTTP/3 support is inferred from the Alt-Svc header (h2/h3); pasted headers show the real protocol in their status line.
  • Caching follows RFC 9111: no-store, private, no-cache, s-maxage > max-age > Expires-Date; CDN-Cache-Control/Surrogate-Control override for shared caches.
  • Security headers use the same deterministic rules as HeaderLens (HSTS, CSP, nosniff, framing, Referrer-Policy, Permissions-Policy, validators, Vary, compression, version disclosure).
  • Technology fingerprints come from response headers (Server, X-Powered-By, vendor headers) and HTML markers (meta generator, well-known asset paths such as /wp-content/, /_next/static/, /_nuxt/). Confidence: high = explicit self-identification, medium = characteristic path, low = weak hint.

For scripts and AI agents

  • JSON API: POST https://httptechnologyexplorer.usefulweb.site/api/v1/calculate (same calculation as this page)
  • Interface description: OpenAPI 3.1 · AI guide: llms.txt
  • MCP server (Streamable HTTP): https://httptechnologyexplorer.usefulweb.site/mcp · tool name http_technology_explorer
Example request
curl -s -X POST https://httptechnologyexplorer.usefulweb.site/api/v1/calculate \
  -H 'content-type: application/json' \
  -d '{…see OpenAPI examples…}'

Related tools

  • CDN Behaviour Explorer – Which CDN serves a URL, whether it caches it (HIT/MISS, Age, TTL) and how, from two requests.
  • HeaderLens – Is a website down? Multi-region status, redirects, TLS and security headers.
  • DNS + Certificate Explorer – DNS records, e-mail security, CAA, live TLS certificate and CT history for a domain.
Feedback