SSL/TLS Certificate Checker
An SSL/TLS certificate checker verifies whether a website has a valid certificate, whether it uses modern TLS (1.2+/1.3), and whether common misconfigurations exist that could expose users to man-in-the-middle attacks or browser warnings.
What it checks
- ✓Certificate validity and expiry date
- ✓TLS version (TLS 1.3 / 1.2 preferred; SSLv3, TLS 1.0, 1.1 are deprecated)
- ✓Cipher suite strength
- ✓Certificate chain completeness
- ✓HSTS (HTTP Strict Transport Security) header presence
- ✓Mixed content warnings
Why it matters
An expired or misconfigured SSL certificate breaks HTTPS, causes browser warnings that drive users away, and can expose data in transit to interception. Google also uses HTTPS as a ranking signal.
Common issues found
Certificate expired or expiring within 30 daysTLS 1.0 or 1.1 still enabled (deprecated)Weak cipher suites (RC4, 3DES)Missing HSTS headerSelf-signed certificate in production
Enter a domain to check
Free, instant SSL/TLS check — no account required
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