SSL Certificate Checker

Check SSL/TLS certificate details for any domain. Verify expiration dates, certificate chain, and security configuration.

100% client-side No signup Free forever
Enter domain without https://

What is SSL/TLS?

SSL (Secure Sockets Layer) and its successor TLS (Transport Layer Security) are cryptographic protocols that provide secure communication over the internet. An SSL certificate:

  • Encrypts data transmitted between browser and server
  • Authenticates the identity of the website
  • Provides a trust indicator (padlock icon) in browsers
  • Is required for HTTPS connections

SSL Certificate Status Meanings

✓
Valid

Certificate is properly configured and not expired

⚠
Expiring Soon

Certificate will expire within 30 days

✗
Invalid/Expired

Certificate has expired or is misconfigured

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How to Use SSL Certificate Checker

  1. Enter the domain name
  2. Click Check SSL
  3. View certificate status
  4. See detailed certificate information
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About SSL Certificate Checker

SSL/TLS certificates encrypt connections and verify website identity. Expired or misconfigured certificates trigger browser warnings that drive visitors away. Our checker monitors your certificate status and identifies configuration issues before they cause problems.

Certificate Details Checked

Comprehensive SSL/TLS analysis includes:

  • Validity period: Issue date, expiration date, days remaining
  • Certificate chain: Root CA, intermediates, and leaf certificate
  • Subject details: Domain names covered, organization info
  • Security config: TLS versions, cipher suites, key strength

Common Issues Detected

Expiration warnings: Certificates approaching expiry need renewal. Chain problems: Missing intermediate certificates cause validation failures. Name mismatches: Certificate doesn't cover the requested domain. Weak configuration: Outdated TLS versions or cipher suites.

Expiration Monitoring

Certificate expiration is the most common SSL problem. Even with auto-renewal, certificates can fail to renew. The checker shows exact expiration dates and days remaining—set calendar reminders for manual renewals or verify auto-renewal is working.

Security Configuration

Modern security requires TLS 1.2 or 1.3. Older protocols (SSL 3, TLS 1.0/1.1) have known vulnerabilities. The checker identifies outdated configurations that may expose visitors to security risks or trigger browser warnings.

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Frequently Asked Questions

What SSL/TLS issues does the checker detect?
We check: certificate validity/expiration, domain name matching, complete certificate chain, strong encryption algorithms, protocol versions (TLS 1.2/1.3), vulnerable configurations, and compliance with security best practices.
What is the difference between SSL and TLS?
SSL (Secure Sockets Layer) is deprecated - all versions have vulnerabilities. TLS (Transport Layer Security) is the modern replacement. "SSL" is commonly used to mean both. You should use TLS 1.2 or 1.3 only. We check which protocols your server supports.
What does "certificate chain incomplete" mean?
Browsers need the complete chain from your certificate to a trusted root CA, including intermediate certificates. If your server only sends the end certificate, some browsers/systems can't verify trust. Install intermediate certificates on your server.
What TLS version should I support?
Enable TLS 1.2 and 1.3 only. TLS 1.0 and 1.1 are deprecated and may be required for PCI compliance reasons to disable. TLS 1.3 is fastest and most secure. We show which versions your server accepts and flag outdated protocols.
What cipher suites should be enabled?
Enable AEAD ciphers (AES-GCM, ChaCha20-Poly1305), disable CBC mode ciphers, RC4, and 3DES. Use ECDHE for key exchange (forward secrecy). Our tool grades your cipher configuration and identifies weak choices to disable.
How do I fix SSL configuration issues?
Most issues require server configuration changes. Use Mozilla SSL Configuration Generator for secure settings. For certificate issues, contact your CA. For protocol/cipher issues, update web server config (nginx, Apache, etc.). We link to relevant guides for each issue found.