SSL Certificate Checker
Check any domain’s SSL/TLS certificate — issuer, SANs, chain, public key, TLS protocol and expiry — instantly and free.
Result for github.com
SSL certificate updated
Subject: github.com
Issuer: Sectigo Public Server Authentication CA DV E36
Covers (SAN): github.com, www.github.com
Valid from: 2026-05-05T00:00:00.000Z
Valid until: 2026-08-02T23:59:59.000Z
Days left: 50
Trusted chain: yes
TLS protocol: TLSv1.3
Cipher: TLS_AES_128_GCM_SHA256
Public key: EC P-256
Chain: github.com → Sectigo Public Server Authentication CA DV E36 → Sectigo Public Server Authentication Root E46 → USERTrust ECC Certification Authority
Serial: E7CECC3B13FB3B7B8A46EA8CD0AEB71C
SHA-256 fingerprint: A7:B8:10:34:CD:43:95:51:C5:0A:29:B5:43:55:25:4A:84:94:2A:0A:99:0C:1A:9E:12:85:6C:85:5B:64:B6:5F
More checks for github.com
How it works
- 1
We open a TLS handshake to the domain on port 443.
- 2
We read the certificate — subject and SANs, issuer chain, validity window, public key and the negotiated TLS protocol and cipher.
- 3
We report expiry, trust status and key rotation — the same signals our monitor watches.
FAQ
Is it free?
Yes — checking a certificate is free and needs no signup.
What are SANs?
Subject Alternative Names are every hostname the certificate is valid for — e.g. example.com and www.example.com on one cert.
Can you alert me before it expires?
Yes. Add the domain in our Telegram bot @gmediatoolsbot and we’ll alert you on changes.
Why does an expired certificate still show details?
We read the certificate even if the chain is expired or untrusted, so you can see exactly what’s wrong.