What this SSL checker tests
Enter a domain and we connect to it the same way a browser does, then check five things:
- Expiry date: how many days until the certificate stops working.
- Trusted chain: whether the certificate leads back to an authority that browsers trust, including the intermediate certificates.
- Hostname match: whether the certificate is actually issued for the domain you entered.
- TLS version: whether the server uses a modern, secure protocol.
- Issuer: who issued the certificate, such as Let's Encrypt or Sectigo.
Common SSL problems and how to fix them
The certificate has expired
Renew it with your certificate provider. If you use Let's Encrypt, automatic renewal has usually stopped working; check certbot or your hosting panel.
Missing intermediate certificate
Some browsers show a warning even though your certificate is valid. Install the full chain file (often fullchain.pem or a CA bundle) instead of only your own certificate.
Certificate doesn't match the domain
The certificate was issued for a different name, for example only example.com but not www.example.com. Reissue it including every name visitors use.
Questions
Is this SSL checker free?
Yes. You can check any public website as often as you like, within a fair rate limit.
Do you store the domains I check?
No. Results are kept in memory for 5 minutes to keep the tool fast, then discarded. See our privacy policy.
How long are SSL certificates valid?
Since March 2026, public certificates can be valid for at most 200 days. That drops to 100 days in March 2027 and 47 days in 2029. Let's Encrypt certificates already last 90 days or less, which is why automatic renewal and expiry alerts matter.
Can I check a site on a private network?
No. For safety, this public tool only checks publicly reachable websites.