Website diagnostics
SSL Checker & Certificate Validator
Verify SSL certificates online with Web Health. Check HTTPS certificate validity, expiration dates, chain of trust, SAN domains, issuer details, and TLS connection parameters.
Understanding SSL/TLS Certificate Verification
Transport Layer Security (TLS) forms the foundation of web privacy and security, encrypting data exchanged between browsers and web servers. Verifying your SSL certificate ensures your domain is protected against eavesdropping, man-in-the-middle attacks, and browser security warnings.
Key SSL Parameters Inspected
- Valid From / Expiration: Active validity window and days remaining before expiry.
- Issuer CA: Sponsoring Certificate Authority (e.g. Let's Encrypt, DigiCert, Sectigo).
- Subject Alternative Names: All covered domain names and subdomains.
- Signature Algorithm: RSA / ECDSA key strength and SHA-256 hashing.
- Chain of Trust: Intermediate and root certificate path validation.
SSL Security Best Practices
- Automate Renewals: Use ACME clients (Certbot, acme.sh) to renew certificates every 60-90 days.
- Disable TLS 1.0 & 1.1: Deprecate legacy TLS protocols and support TLS 1.2 and TLS 1.3 only.
- Bundle Full Chain: Serve both leaf and intermediate certificates to prevent mobile trust errors.
- Enable HSTS: Instruct browsers to permanently enforce HTTPS via strict transport headers.
Frequently Asked Questions
An SSL/TLS certificate check connects to a web server over port 443 to inspect its security certificate. It validates whether the certificate is active, properly installed, trusted by web browsers, issued by a valid Certificate Authority (CA), and covers the requested domain name.