SSL Checker
Inspect SSL certificates
SSL Checker is on the roadmap. In the meantime, explore the other encoding & security.
What is SSL Checker?
Inspect the SSL/TLS certificate of any public HTTPS site — issuer, subject, validity dates, supported protocols, and the full certificate chain. The tool fetches the certificate via a public lookup API and displays the parsed result; nothing is typed or stored on our servers. Useful for verifying a site's certificate is valid, checking expiry before renewal, or auditing a domain you're about to integrate with.
How do I use SSL Checker?
- Enter a domain (e.g. "example.com") — no https:// prefix needed.
- Click Check.
- Read the issuer, subject, validity, expiry, and certificate chain.
When should I use SSL Checker?
SSL Checker reads a public certificate. For decoding a JWT token, use JWT Decoder. To generate a hash of a downloaded certificate file for comparison, use Hash Generator. For password strength scoring, use Password Strength.
Does it actually connect to the site?
Yes — the tool fetches the certificate via a public lookup API. The site's server logs may record the lookup; the certificate itself is public information so this is harmless.
What does "Valid" mean?
The certificate is currently in its validity window (not expired, not yet to start), is signed by a trusted CA in the public root store, and matches the requested domain. All three conditions must hold for browsers to accept it without warning.
My certificate is valid but my browser shows a warning — why?
Common reasons: missing intermediate certificates in the chain, name mismatch (e.g. www vs root), or a deprecated protocol (TLS 1.0 / 1.1). The chain view helps debug each.
Is my file uploaded anywhere?
No. Everything runs in your browser. Your files never leave your device, and there is no server component for this tool.