Mozilla http scanner

Overview

Mozilla’s HTTP Observatory scans sites for HTTP security best practices (headers, TLS, CSP) and returns a score.

⚠️ Status (verified 2026-08): the API returned HTTP 502 (server error) at check time — the service appears to be down or having issues. Verify from your network before relying on it.

What it provides

curl "https://http-observatory.security.mozilla.org/api/v1/analyze?host=mozilla.org"

{
  "state": "FINISHED",
  "grade": "A+",
  "score": 135,
  "tests_failed": 0
}

Notes

• Analyze: POST /api/v1/analyze?host={domain}; results: GET /api/v1/analyze?host={domain}.
• Returns a letter grade plus detailed test results.

FAQ

Is the Observatory free? Yes — free and keyless.

Why 502? Our 2026-08 check hit a server error — verify from your network.

What does it scan? HTTP headers, TLS, CSP, and security best practices.