HTTP Security Header Checker (Live)
In-Browser
Fetch a live URL and grade its HTTP security headers: HSTS, CSP, X-Content-Type-Options and more.
Web SecurityDomain
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Curated security tools and interactive browser utilities for learning, research, and responsible testing.
9 tools
Fetch a live URL and grade its HTTP security headers: HSTS, CSP, X-Content-Type-Options and more.
Check and grade a domain's SPF, DMARC and (optionally) DKIM records for email spoofing protection.
Fetch a URL live and inspect status, redirect chain, every response header, detected tech and timing.
Check a domain's CAA records — which Certificate Authorities are authorised to issue its TLS certificates.
Parse a CVSS 3.1 or 4.0 vector, expand every metric in plain English, and compute the 3.1 base score.
Paste raw email headers to reconstruct the delivery hop path and read SPF, DKIM, and DMARC results.
Paste HTTP response headers and get a graded report on HSTS, CSP, X-Frame-Options, and more.
Decode a JWT and statically review its header and claims.
Break a User-Agent string into browser, version, operating system, and device — and spot bots.