SSL/TLS Certificate

An SSL/TLS certificate is a digital credential that enables encrypted HTTPS connections and proves a site owns its domain.

When a browser connects over HTTPS, the server presents its TLS certificate. If it is valid and trusted, the connection is encrypted and the padlock appears. If it is expired, misconfigured, or issued for the wrong domain, browsers show a security warning that blocks users.

Because certificates expire (often every 90 days), monitoring their validity and expiry prevents the classic, avoidable outage of a lapsed certificate.

Is your SSL certificate valid and trusted?

Check the validity, chain and domain of your TLS certificate before browsers block your visitors with a security warning. Free, in seconds.

Check certificate

Related terms

SSL ExpirySSL expiry is the date an SSL/TLS certificate stops being valid, after which browsers reject the connection.DNS (Domain Name System)The Domain Name System (DNS) translates human-readable domain names like deinkunde.com into the IP addresses computers use to connect.HTTP Status CodeAn HTTP status code is a three-digit number a server returns to indicate the outcome of a request, such as 200 (OK), 404 (Not Found), or 500 (Server Error).

Start monitoring in minutes

EU-hosted uptime monitoring with multi-location confirmation that kills false alarms, white-label for agencies.

Start Free Trial