CertH Public API
Plug CertH TLS grading into your tooling, CI or dashboards. The free tier needs no signup; an API Key unlocks full history.
Instant scan
POST /api/scan
Real-time TLS grade for any domain — 0-100 score and A+ to F, no auth required.
Score history
GET /api/public/domains/:domain/history
45 days free; API Key unlocks 90 days (Pro) / 365 days (Agency).
Leaderboard data
GET /api/leaderboard
Global TLS health rankings with grade, industry and region filters plus pagination.
Try it live
Call the public endpoints right here — no signup, no copy-paste. Requests go out from this page and return live data.
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Requests are sent same-origin; POST /api/scan persists under throttling (≤20 new domains per IP daily, ≤1 snapshot per domain per hour).
Auth & free tier
· Instant scan & 45-day history: no auth, works out of the box.
· Deeper history: sign in at thedashboardto get a free API Key (ch_ prefix), send it via the x-api-key header.
· Rate limits: ≤20 new domains persisted per IP daily; at most 1 snapshot per domain per hour.
Full API reference
Every endpoint, parameter, response example and error code.
FAQ
Do I need an account to use the API?
No — instant scan and 45-day history work without signup; an API Key unlocks deeper history.
What are the API rate limits?
≤20 new domains persisted per IP daily; at most one snapshot per domain per hour.
How do I get longer history?
Upgrade to Pro (90 days) or Agency (365 days) and send your API Key via the x-api-key header.