How does CertH grade a TLS setup?

It sends a ClientHello to port 443, reads the certificate chain and negotiated parameters, weights protocol versions, cipher strength, key size, validity, hostname match and chain length into a 0-100 score, then maps it to A+ … F following SSL Labs semantics.

Does CertH store my data?

Only public TLS data is processed. After signup we keep just your email, watched domains, alert rules and hashed API keys; you can delete your data or close your account at any time.

Điều khoản dịch vụ

Read this before using CertH: scope of service, acceptable use, the nature of the grades and liability terms.

By using CertH — this site, the public API and the grade badges — you agree to the terms below. If you use it on behalf of an organization, confirm that you are authorized to accept them.

Scope of the service

CertH provides public TLS/SSL configuration scanning, grade leaderboards, score history, and badge/API endpoints. A scan only reads what the target voluntarily returns on port 443 during a handshake — there is no offensive behaviour involved. Scan only domains you own, or that you are authorized to assess.

Acceptable use

You may not use the service to stress-test, port-scan or otherwise interfere with third parties; you may not bypass rate limits, spoof your origin, or substitute bulk page scraping for the public endpoints; you may not use results for any unlawful purpose. In case of abuse we may throttle or terminate your access immediately and without prior notice.

Rate limits & availability

The service runs on the Cloudflare free tier with rate limits and caching on instant scans, the API and badges (at most one stored snapshot per domain per hour, badges edge-cached for one hour). At peak times you may see queuing, degradation or temporary unavailability. We keep tuning quotas and features, but make no availability commitment of any kind.

Nature of the grades

Grades are an automated reading of one handshake; they are operational reference only. They are not a penetration test, not a security or compliance certification, and not a guarantee about the safety of your system. Different tools use different methodologies and may disagree; validate any change elsewhere before rolling it out in production.

Badges, API & branding

You may freely embed CertH badges on your site, README or docs, but you must not alter the score or grade shown, must not use the CertH name or logo to imply endorsement or partnership, and must not bulk-copy API data to power a directly competing product. When you cite us, please link back to certh.csr.plus.

Accounts & payment

Public scanning and the leaderboard work without an account. An account lets you watch domains, keep longer history and configure alerts. Paid subscriptions are not live yet; if they launch, pricing, billing cycles and refund rules will be published on this page first — until then, anyone charging "on behalf of CertH" is not us.

Liability & changes

To the maximum extent permitted by law, we are not liable for indirect damages, data loss or business interruption arising from use of, or inability to use, this service. When the terms change we update the date on this page; continued access means you accept the latest version. Questions or appeals: certh@csr.plus.

Affiliate links & advertising

We earn revenue from affiliate links labelled "Advertisement", which helps cover scanning and hosting costs. These links never buy influence over our results: no domain can pay to improve its score, grade or leaderboard position, and we do not offer paid grade changes. Services purchased through an affiliate link are provided and fulfilled solely by that vendor, whose terms, refunds and support apply.

Last updated: 2026-11-03