SSL Certificate Checker

Verify SSL/TLS certificate validity, expiry date, certificate chain, and security configuration.

Certificate Chain Expiry Check Security Analysis

Understanding SSL/TLS Certificates

SSL/TLS certificates encrypt traffic between browsers and servers, protecting users from eavesdropping and ensuring site authenticity.

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Certificate Validity

SSL certificates have a fixed validity period (typically 90 days to 2 years). Expired certificates cause browser security warnings and break HTTPS connections for visitors.

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Certificate Chain

A certificate chain links your server certificate to a trusted Root CA via intermediate certificates. Browsers verify the full chain to establish trust for the connection.

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TLS Protocol Versions

TLS 1.3 is the current standard offering the best security and performance. TLS 1.2 is still acceptable, while TLS 1.0 and 1.1 are deprecated and should be disabled.

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Certificate Fingerprint

A fingerprint is a cryptographic hash of the certificate that uniquely identifies it. Use SHA-256 fingerprints to verify a certificate's authenticity and detect any tampering.

Frequently Asked Questions

What does an SSL checker do? expand_more

An SSL checker connects to a server on port 443, downloads its TLS certificate, and verifies the chain of trust, expiration date, protocol version, and cipher configuration.

How do I know if my SSL certificate is valid? expand_more

A valid certificate is issued by a trusted Certificate Authority, has not expired, matches the domain name, and has a complete chain of trust.

What is a certificate chain? expand_more

A certificate chain links your server's certificate to a trusted root CA through one or more intermediate certificates. Browsers need the full chain to verify trust.

What TLS version should I use? expand_more

TLS 1.3 is the current standard offering the best security and performance. TLS 1.2 is still acceptable. TLS 1.0 and 1.1 are deprecated and should be disabled.

What happens when an SSL certificate expires? expand_more

Browsers show a security warning, users cannot access the site without clicking through the warning, and search engines may reduce rankings.

How often should I check my SSL certificate? expand_more

Run spot checks after any certificate renewal or server change. For ongoing monitoring, set up automated alerts for certificates expiring within 30 days.

What is a self-signed certificate? expand_more

A self-signed certificate is not issued by a trusted CA. Browsers flag it as untrusted. It is suitable for internal services but not public-facing websites.