SSL/TLS Checker
Check SSL certificate: expiration, chain of trust, protocol, encryption
SSL/TLS check validates a site's certificate chain: root CA, intermediates, and leaf certificate. The tool reports expiry, issuer, supported protocols (TLS 1.2/1.3), ciphers, OCSP status, and warns about errors like expiration or domain mismatch. Useful for debugging NET::ERR_CERT_* issues and monitoring SSL expiry.
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Why teams trust us
How it works
Enter domain
TLS chain verified
Expiry date & vulnerabilities
What Does the SSL Check Cover?
SSL/TLS is the encryption protocol that protects data between the browser and server. Our tool analyzes the certificate, chain of trust, TLS version, and knownvulnerabilities.
Certificate Details
Issuer, validity period, signature algorithm, covered domains (SAN), and validation type (DV/OV/EV).
Chain of Trust
Full chain verification: from leaf certificate through intermediates to root CA.
TLS Analysis
Protocol version (TLS 1.2/1.3), cipher suites, Perfect Forward Secrecy (PFS) support.
Expiry Alerts
Set up a monitor — get Telegram and email alerts 30/14/7 days before expiration.
DV vs OV vs EV Certificates
- Confirms domain ownership only
- Issued in minutes automatically
- Free via Let's Encrypt
- Suitable for most websites
- Most common certificate type
- Organization (OV) or Extended Validation (EV)
- Issued in 1-5 business days
- Costs $50 to $500/year
- For finance, e-commerce, government sites
- Increases user trust
Who uses this
DevOps
SSL certificate monitoring
Security
TLS config audit
SEO
HTTPS as ranking factor
E-commerce
customer trust
Common Mistakes
www and subdomains.Best Practices
Strict-Transport-Security header forces browsers to always use HTTPS.Get more with a free account
SSL certificate monitoring, check history and alerts 30 days before expiry.
Sign up freeSSL/TLS Certificate Checker
Verify SSL/TLS certificates for any domain: expiration date, issuer, chain validity, supported protocols (TLS 1.2, 1.3), cipher suites, and OCSP status. Our tool connects directly to the server and performs a real TLS handshake. Essential for monitoring certificate expiration, debugging HTTPS issues, and ensuring secure configuration.
Essential checks include certificate expiry date, trust chain completeness, TLS protocol versions (1.2/1.3), cipher suite strength, and OCSP stapling support. The tool also detects common issues like mixed content, certificate name mismatches, and weak key sizes.
Schedule regular SSL checks or set up monitoring to get alerts before certificates expire. Combine with security header analysis for a complete website security audit. For DNS-related issues, use our DNS lookup to verify CAA records and name server configuration.
Learn more
Frequently Asked Questions
What is SSL/TLS?
SSL/TLS is an encryption protocol that secures data between a browser and server. SSL (Secure Sockets Layer) is the legacy name; TLS (Transport Layer Security) is currently used. An SSL certificate enables HTTPS connections.
How to check if a site has SSL?
Enter the URL in the form above — our tool will check the certificate, chain of trust, protocol, cipher, and validity period. You can also click the lock icon in the browser address bar for basic information.
What does an expired SSL certificate mean?
An expired certificate means the browser will show a security warning and users cannot access the site without acknowledging the risk. This critically affects trust, SEO, and conversion.
What is a certificate chain?
A certificate chain is the sequence from your certificate through intermediates to the root CA. Browsers verify the entire chain to establish trust. An incomplete chain may cause errors on some devices.
How often should SSL certificates be renewed?
Let's Encrypt certificates last 90 days and renew automatically. Commercial certificates are typically issued for 1 year. It is recommended to set up expiry monitoring to avoid missing renewals.
What is the difference between DV, OV, and EV certificates?
DV (Domain Validation) confirms domain ownership only, issued in minutes. OV (Organization Validation) verifies the organization, issued in 1-3 days. EV (Extended Validation) has maximum verification, formerly showed a green bar in browsers.
Why is HTTPS important for SEO?
Google has used HTTPS as a ranking factor since 2014. Sites without HTTPS are marked as "Not Secure" in Chrome, reducing user trust and increasing bounce rate. HTTPS is also required for HTTP/2 and Service Workers.
Related guides
Longer-form reading on this topic from the knowledge base.
Never have your SSL expire unexpectedly
Add the domain — get 14-day and 3-day warnings in Telegram, email, Slack, webhook.