SSL Checker
Make sure a site's certificate is valid, complete and not about to expire.
- Online check — sends only the domain you type
- 100% free
- No sign-up
How to check an SSL certificate
- Type a domain (and port if not 443).
- Read the validity, expiry, grade and chain.
- Review protocol support and the names covered.
About SSL Checker
Check a website’s SSL/TLS certificate.
It works in your browser for speed and privacy, remembers your settings on this device, and every result can be copied, downloaded or shared.
Good for
- Monitoring certificate expiry
- Fixing chain and trust errors
- Hardening TLS settings
Tip: Turn off TLS 1.0 and 1.1 — every modern browser supports TLS 1.2 and 1.3.
Frequently asked questions
What does the grade mean?
A+ = valid certificate with TLS 1.3 and no outdated protocols; A = valid with TLS 1.2; B = old TLS 1.0/1.1 still enabled; C = weak key; F = expired, untrusted or wrong name.
Why does the chain matter?
Browsers need the intermediate certificates to trust yours. A missing intermediate causes errors on some devices even when the site works in your browser.
Can I check another port?
Yes — set the port, for example 8443, 465 (SMTPS) or 993 (IMAPS).
How do I get reminded before expiry?
Check the days left here; most certificates now last 90 days or less, so automate renewal (for example with Let’s Encrypt / certbot).
How is the check made?
Our server connects to the site you enter to read its certificate and TLS settings, because browsers don't expose them. Results aren't saved.