No sign-up
Mozilla Observatory
Audit security headers and TLS configuration.
What it is
You enter a domain and get a grade with concrete recommendations about Content-Security-Policy, HSTS, secure cookies, referrer policy and TLS configuration, with links to the documentation for each point.
Best for
Hardening a site's headers in an afternoon.
What the free plan includes
- No sign-up
- Analyses public domains
- Indicative results, not a full audit
Free plans change often. Confirm the limits on the official page before deciding.
