SSL Certificate Checker
NetworkCheck SSL certificate validity, expiry date, issuer and security details for any website instantly.
Enter domain without https:// — e.g. github.com
About the SSL Certificate Checker
Check SSL certificate validity, expiry date, issuer and security details for any website instantly. TrendPro's SSL Certificate Checker is completely free to use with no account or sign-up required. Your data is processed directly in your browser and is never sent to any server or stored anywhere.
How to Use the SSL Certificate Checker
- 1
Enter the domain name you want to check — e.g. google.com or yourwebsite.com.
- 2
Click Check SSL to analyse the SSL certificate.
- 3
View the certificate validity, issuer, expiry date and days remaining.
- 4
Check for warnings — certificates expiring within 30 days are highlighted in amber, expired in red.
- 5
Review the Subject Alternative Names to see all domains the certificate covers.
Frequently Asked Questions
What is an SSL certificate?
An SSL (Secure Sockets Layer) certificate is a digital certificate that authenticates a website's identity and enables an encrypted HTTPS connection. Websites with SSL certificates show a padlock icon in the browser address bar, indicating secure communication.
What happens when an SSL certificate expires?
When an SSL certificate expires, browsers show a security warning to visitors and block access to the site. This can cause a significant drop in traffic and trust. Most certificates need to be renewed annually or every 90 days (for free Let's Encrypt certificates).
How long are SSL certificates valid?
Most commercial SSL certificates are valid for 1 year. Free Let's Encrypt certificates are valid for 90 days and need to be renewed more frequently. Some older certificates were valid for 2 years, but browsers no longer trust certificates with validity longer than 398 days.
What is a self-signed certificate?
A self-signed certificate is signed by the website owner rather than a trusted Certificate Authority (CA). Browsers show security warnings for self-signed certificates because they cannot verify the website's identity. They should only be used for internal/development purposes.
What are Subject Alternative Names (SANs)?
Subject Alternative Names are additional domain names that an SSL certificate is valid for. For example, a certificate for example.com might also cover www.example.com, mail.example.com and other subdomains. Wildcard certificates cover all subdomains (*.example.com).
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