SSL Certificate Checker
Check HTTPS connectivity, HSTS configuration, and TLS security for any domain.
What is an SSL Certificate?
SSL/TLS certificates encrypt the connection between your browser and a website, ensuring data privacy and integrity. A valid certificate confirms the website's identity and enables the HTTPS padlock icon. Expired or misconfigured certificates create security warnings that drive visitors away.
Why check your SSL certificate?
An expired or misconfigured SSL certificate is one of the fastest ways to lose visitor trust. Browsers will display a full-page warning, and Google treats HTTPS as a ranking signal — so a broken certificate can hurt both traffic and SEO.
Common SSL issues
- Expired certificate — browsers block access entirely until renewed
- Certificate name mismatch — the domain on the cert doesn't match your URL
- Incomplete certificate chain — missing intermediate certificates cause trust errors
- Mixed content — loading HTTP resources on an HTTPS page triggers warnings
- Weak protocols — older TLS versions (1.0, 1.1) are considered insecure
Tips
- Set a calendar reminder 30 days before expiry — or use auto-renewing certs (e.g. Let's Encrypt)
- Always include the full certificate chain when installing your cert
- Enforce TLS 1.2+ and disable older protocols on your server
- Use HSTS headers to tell browsers to always use HTTPS
- Check all subdomains too — a wildcard cert covers
*.example.combut not the root