DangKit

SSL Certificate Checker

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Check SSL certificate details and expiry

Processed in your browser
HTTPS encrypted transfer
No data sent to servers

What is SSL Certificate Checker?

SSL Certificate Checker inspects the TLS/SSL certificate of any website, showing the certificate issuer, validity dates, subject alternative names (SANs), protocol version, and whether the certificate is trusted by major browsers.

When to use this tool

  • Verifying a website's SSL certificate before sensitive operations
  • Checking certificate expiration dates
  • Confirming which domains a certificate covers
  • Debugging SSL/TLS handshake failures

How it works

Connects to the target domain over HTTPS and retrieves the TLS certificate chain. Parses the certificate to extract the issuer, subject, validity period, SANs, serial number, and protocol details. Compares the issuer against known trusted certificate authorities.

Security Guidelines

  • A certificate expiring within 30 days should be renewed immediately
  • Wildcard certificates (*.example.com) only cover one level of subdomains
  • Self-signed certificates are not trusted by browsers โ€” use them only for internal/dev environments
  • Check that the certificate chain is complete โ€” missing intermediate certificates cause trust errors

About SSL Certificate Checker

Check SSL certificate details and expiry It runs entirely in your browser โ€” no files are uploaded to any server, ensuring complete privacy and instant results.

  • โ€ขLook up IP address geolocation
  • โ€ขReference all HTTP status codes
  • โ€ขParse and analyze URL components
  • โ€ขCheck common port availability
Related reading โ†’

Last updated: 2025-01-15

FAQ

Check SSL certificate details and expiry

Yes, completely free. No signup required.

Yes. Runs entirely in your browser, no files uploaded.

Yes, works on any device with a modern browser.

No, everything runs in your browser.

SSL Certificate Checker โ€” Free Online Tool | DangKit