SSL Checker Tools

Browse all RunSSLCheck tools. Check SSL certificate expiry, chain, trust, hostname match, TLS versions, and more — by feature, error type, CA, or platform.

Try:
  • Live TLS handshake
  • Trust & chain validation
  • Expiry countdown
  • TLS 1.0–1.3 detection

SSL Certificate Checker Tools

Inspect every aspect of an SSL certificate — expiry, chain, trust, hostname, TLS versions, and more.

SSL Certificate Expiry Checker

Free SSL certificate expiry checker. Enter any domain to see the expiration date, days remaining, and whether renewal is needed. Live check, no cached data.

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SSL Certificate Chain Checker

Check your SSL certificate chain. Visualize every cert from server to trusted root, identify missing intermediates, and download PEM files. Free, no signup.

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SSL Trust Checker

Check if your SSL certificate is trusted by major browsers. RunSSLCheck validates against the system trust store via a live TLS handshake. Free, instant, no signup.

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SSL Hostname Checker

Check if your domain is covered by its SSL certificate. RunSSLCheck validates the Common Name and all SANs for hostname match. Diagnose hostname mismatch errors instantly.

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TLS Version Checker

Check which TLS versions (1.0, 1.1, 1.2, 1.3) a server supports. Identify deprecated protocols that violate PCI DSS and put users at risk. Free, live probe.

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SSL Checker for Any Port

Check SSL certificates on non-standard ports. Enter hostname:port (e.g. mail.example.com:587) and RunSSLCheck connects directly. Supports IMAPS, LDAPS, HTTPS alternatives.

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Wildcard SSL Certificate Checker

Check wildcard SSL certificates. Enter any covered subdomain to verify trust, expiry, and the full SAN list. Free online wildcard SSL certificate checker.

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Subdomain SSL Checker

Check SSL on any subdomain. Verify whether a subdomain is covered by a dedicated cert, wildcard, or SAN entry. Free subdomain SSL certificate checker, no signup.

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SSL Certificate Details Checker

View full SSL certificate details: issuer, subject, serial number, SHA-256 fingerprint, key type, key size, SANs, and signature algorithm. Free online cert analyzer.

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HTTPS Checker

Check if your website has a valid, trusted HTTPS connection. Verify SSL certificate trust, chain, and expiry — everything needed to confirm HTTPS is properly configured.

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SSL Error Diagnostic Tools

Diagnose specific SSL errors and certificate problems. Find the exact cause of browser security warnings.

SSL Certificate Expired Checker

Check if an SSL certificate has expired. Enter any domain to see expiry status, the exact expiration date, and steps to fix an expired certificate. Free, instant.

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SSL Certificate Not Trusted Checker

Diagnose 'certificate not trusted' SSL errors. RunSSLCheck checks trust, certificate chain, root CA, and identifies why browsers reject your certificate. Free, instant.

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SSL Chain Incomplete Checker

Check for incomplete SSL certificate chains and missing intermediate certificates. RunSSLCheck shows exactly where the chain breaks. Free, live chain checker.

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SSL Hostname Mismatch Checker

Diagnose SSL hostname mismatch errors. RunSSLCheck checks the Common Name and SANs to identify exactly which domains the certificate covers and why the mismatch occurs.

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SSL Certificate Not Yet Valid Checker

Diagnose 'certificate not yet valid' SSL errors. RunSSLCheck reads the notBefore date to identify certificates served before their activation date. Free, instant.

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Self-Signed Certificate Checker

Detect self-signed SSL certificates that cause browser trust errors. RunSSLCheck identifies when a certificate is signed by itself rather than a trusted CA. Free, instant.

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Deprecated TLS Version Checker

Check if a server still supports deprecated TLS 1.0 or TLS 1.1. These protocols are insecure and banned by PCI DSS. Free live TLS version probe — no cached data.

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SSL Certificate Expiring Soon Checker

Check if an SSL certificate is expiring soon. RunSSLCheck shows exact expiry date, days remaining, and renewal urgency. Catch expiring certs before visitors see warnings.

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SSL Checkers by Certificate Authority

CA-specific guidance alongside live certificate verification. Check certs from Let's Encrypt, DigiCert, Sectigo, and more.

SSL Checkers by Platform

Platform-specific guidance for WordPress, Shopify, Cloudflare, AWS, Nginx, and more.

How the SSL checker works

Check any SSL certificate online in three simple steps — no signup, no downloads.

1. Enter a hostname

Type any domain or subdomain — for example example.com or mail.example.com. You can paste a full URL; we'll clean it up automatically. Add :port for non-standard ports.

2. We connect live

RunSSLCheck opens a real TLS connection to the server and inspects the exact certificate it presents — no cached data and no third-party API.

3. Read your results

See trust status, hostname match, expiry countdown, the full certificate chain, key strength, and which TLS versions are enabled.

Everything you need to check SSL certificates

A complete SSL certificate checker that goes beyond a simple pass or fail.

Trust & installation check

Confirms the certificate is valid, trusted by major browsers, and that all intermediate certificates are correctly installed.

SSL certificate expiry check

Shows the exact validity window and a clear countdown of days remaining so you can renew before visitors ever see a warning.

Full certificate chain

Visualizes the path from your server certificate up to the trusted root CA, with downloadable PEM for every certificate.

Key & protocol analysis

Reports key type and size, signature algorithm, and detects every supported TLS version from 1.0 to 1.3.

Frequently asked questions

Common questions about this SSL checker tool.