SSL certificate
An SSL/TLS certificate proves a server's identity and encrypts data between your browser and the site.
In plain English
The thing that makes the padlock show in your browser: it proves the site is who it says it is and scrambles data so others can’t read it in transit.
SSL (Secure Sockets Layer) and its successor TLS (Transport Layer Security) provide encrypted connections between your browser and a website. A certificate is issued by a trusted Certificate Authority (CA) and binds a domain (or hostname) to a public key.
When a certificate is valid, you see the padlock and HTTPS. Expired or invalid certificates can mean the connection is not secure or the site is misconfigured. Our SSL checker shows issuer, validity dates, and days until expiry.
Examples & Usage
Certificate Details
Issuer: Let's Encrypt Authority X3
Common Name: *.example.com
Expiry: Nov 24, 2026