Online tool

Check SSL certificate expiration

See which certificate a public HTTPS host presents, who issued it, and how many days remain before expiration.

This is a one-time check: it does not create a monitor or send notifications.

Need continuous monitoring?

Know about certificate expiration in advance

SSL monitoring runs automatically and sends a warning before visitors see a browser certificate error.

Set up SSL monitoring

Certificate data

A one-time check of the current HTTPS certificate

The tool checks the certificate for the exact host, so a subdomain certificate is not replaced with data for the root domain.

Exact host

For api.example.com, the certificate for api.example.com is checked—not only the registration for example.com.

Validity period

Start and end dates are parsed from the certificate, and days remaining stay signed for already expired certificates.

No internal scanning

The tool accepts public HTTPS targets only and never connects to local or infrastructure networks.