SSL Certificate Checker
Analyse SSL/TLS certificates, check expiry dates, and get security grades for any website.
Enter a domain name or URL to analyse its SSL certificate. This tool checks certificate validity, expiry dates, issuer information, and provides an overall security grade.
How to Use This Tool
- Enter a Domain: Type the domain name (e.g., example.com) or full URL of the website you want to check.
- Click Check Certificate: The tool will connect to the server and retrieve the SSL certificate information.
- Review the Results: Check the security grade, certificate details, and any issues or warnings.
- Take Action: If issues are found, work with your hosting provider or certificate authority to resolve them.
Understanding SSL Certificate Grades
- A Excellent - No issues, strong security
- B Good - Minor improvements possible
- C Fair - Some security concerns
- D Poor - Significant issues found
- F Failing - Critical security problems
Common SSL Certificate Issues
| Issue | Description | Solution |
|---|---|---|
| Expired Certificate | The certificate has passed its validity date | Renew the certificate with your CA |
| Domain Mismatch | The certificate doesn't match the domain name | Obtain a certificate for the correct domain |
| Self-Signed | Not issued by a trusted Certificate Authority | Use a certificate from a trusted CA |
| Weak Key | RSA key is less than 2048 bits | Generate a new certificate with stronger key |
| Weak Algorithm | Using deprecated SHA-1 or MD5 | Request certificate with SHA-256 signature |
Frequently Asked Questions
An SSL/TLS certificate is a digital certificate that authenticates a website's identity and enables an encrypted connection. SSL stands for Secure Sockets Layer, whilst TLS (Transport Layer Security) is its successor. When a website has a valid SSL certificate, browsers display a padlock icon in the address bar.
An expired or invalid SSL certificate can cause browsers to display security warnings, deterring visitors from your website. Search engines like Google also use HTTPS as a ranking factor, so maintaining a valid SSL certificate is important for both security and SEO.
The security grade reflects the overall security posture of the SSL certificate and its configuration. Grade A indicates excellent security with a valid certificate, strong encryption, and proper configuration. Lower grades may indicate issues like weak encryption algorithms, certificate problems, or missing security features.
A certificate chain (or chain of trust) is a sequence of certificates where each certificate is signed by the next certificate in the chain. The chain typically includes the end-entity certificate (your domain), intermediate certificates, and a root certificate from a trusted Certificate Authority (CA).
We recommend checking your SSL certificate at least monthly, and setting up automated monitoring to alert you before expiry. Most certificates are valid for 1 year (or 90 days for Let's Encrypt), so regular monitoring helps prevent unexpected expiry and website downtime.
Related Tools
- Security Header Checker Check HTTP security headers
- What's My IP Find your public IP address
- Password Generator Generate secure passwords
- Hash Generator Generate MD5, SHA hashes
Quick Tips
-
Renew Early
Renew certificates at least 30 days before expiry
-
Use Strong Keys
RSA 2048-bit or EC 256-bit minimum
-
Include All Domains
Add www and non-www versions to SANs
-
Monitor Regularly
Set up automated certificate monitoring
Popular Certificate Authorities
- Let's Encrypt - Free, automated certificates
- DigiCert - Enterprise-grade certificates
- Sectigo (Comodo) - Wide range of options
- GlobalSign - Business certificates
- GoDaddy - Domain and hosting bundles