HttpFixer vs Mozilla Observatory
Mozilla Observatory gives your site a letter grade. HttpFixer gives you the exact configuration to improve it — for your specific stack. Both are free. Here is how they compare.
Side-by-side comparison
| Feature | Mozilla Observatory | HttpFixer |
|---|---|---|
| Scans security headers | Yes | Yes |
| Letter grade (A–F) | Yes | — (pass/fail per header) |
| Stack-specific fix config | No — recommendations only | Yes — Nginx, Vercel, Cloudflare, Express, Apache, Caddy, FastAPI |
| Stack detection from live headers | No | Yes — reads Server header to detect your stack |
| CORS preflight testing | No | Yes — CORSFixer sends real OPTIONS requests |
| OAuth error diagnosis | No | Yes — OAuthFixer with provider-specific fixes |
| CSP scanning from live URL | No | Yes — CSPFixer scans all resources your page loads |
| PageSpeed config generation | No | Yes — SpeedFixer via live PSI API |
| Mozilla brand and authority | High | — (independent tool) |
| Open source | Yes | Yes (MIT) |
| No signup required | Yes | Yes |
| Client-side processing | No — server-side | Yes — nothing sent to servers |
The core difference
Mozilla Observatory is a checker. It tells you your grade and which headers are missing or misconfigured. It does not tell you what to paste into your nginx.conf to fix them.
HttpFixer is a fixer. After detecting which headers are missing, it reads the Server header from your response, identifies your stack, and generates the exact add_header directives, vercel.json headers block, or Cloudflare Transform Rule — ready to copy and paste.
Example: missing X-Frame-Options
| Observatory output | HttpFixer output | |
|---|---|---|
| What you see | X-Frame-Options header not implemented — minus 20 points | Detected Nginx — here is your fix: |
| Config provided | Link to MDN documentation | add_header X-Frame-Options "SAMEORIGIN" always; |
When to use Observatory
- You want a standardized letter grade for stakeholders or compliance
- You want Mozilla's official perspective on your security posture
- You are researching your overall security level before starting fixes
When to use HttpFixer
- You know you have a problem and need the exact config to fix it
- You need stack-specific output for Nginx, Vercel, Cloudflare, or Express
- You need to fix CORS errors, CSP violations, or OAuth failures — not just header presence
- You want to go from failing Observatory to passing — with copy-paste configs
The workflow most developers use
Run Observatory to get a grade and understand the full picture. Then use HttpFixer to get the exact configs for each failing item. Observatory for diagnosis — HttpFixer for the fix.