Free SSL certificate checker
Check any website's certificate: who issued it, when it expires, whether browsers trust it and whether it covers the name.
What it checks
Expiry
The date it runs out and the days left, with a warning inside 30 days.
Trusted by browsers
Whether it chains to an authority browsers trust, or is self-signed, expired or missing its intermediate certificates.
Covers the name
Whether the name you entered is on the certificate, including wildcards.
Issuer and names
Who issued it and every name it covers.
Connection
The TLS version the server agreed to.
Questions
What happens when a certificate expires?
Browsers show a full-page security warning and most visitors leave. Email and other services that use the certificate can stop connecting too.
Why does it say browsers do not trust my certificate?
Usually the certificate is self-signed, has expired, or the server does not send the intermediate certificates that connect it to a trusted authority.
Which port does it check?
Port 443, the standard HTTPS port, at the address the name points to. Names that point to private or internal addresses cannot be checked from the internet.
Is anything stored?
No. The name you enter is checked and the answer is shown to you; the checker does not save or log it.
Also free: Free email security checker · Free website security headers checker · Free DNS lookup · All free tools
Check every customer, every day
TechSavve RMM checks websites, DNS, mail and certificates for every customer directly from the platform, and tells you before a certificate runs out.