About certs.lol

certs.lol is fast, API-first TLS scanning built for developers who live in the terminal.

What it does

Scans any domain or IP for its complete TLS configuration in under 5 seconds: protocol support, cipher suites, certificate chain, post-quantum readiness, ECH, HSTS, HTTP/3, DNSSEC, and more. Returns a letter grade with transparent methodology.

How it works

curl https://certs.lol/stripe.com | jq

Same URL, content-negotiated. curl gets JSON, your browser gets a formatted report. No API keys, no accounts, no tracking.

Built by

certs.lol is part of the .lol family — free developer tools for DNS, TLS, HTTP, email, and domain intelligence.

• certs.lol — TLS/SSL scanner (you are here)
• ns.lol — DNS toolkit
• xhttp.lol — HTTP response debugger
• vrfy.lol — Email validation
• yoke.lol — Full domain intelligence

Open source: github.com/yokedotlol/certs-lol

Contact

hello@certs.lol