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. The TLS probe that powers certs.lol is the same one that feeds yoke.lol's security analysis.

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