~/tools / ssl-checker
SSL Checker
Check SSL certificate expiry, chain validity, TLS version and cipher. Catches expired certs, weak crypto and chain issues.
[ OK ]
Valid for 50 more days.
── output ─────
- Issued to
- protonmail.com
- Issued by
- R12
- Valid from
- 2026-03-13
- Valid until
- 2026-06-11 (50 days)
- TLS version
- TLSv1.3
- Cipher
- TLS_AES_256_GCM_SHA384
- Key
- RSA · 4096 bit
- Signature
- sha256WithRSAEncryption
- Forward secrecy
- yes
- Self-signed
- no
- Must-staple
- no
- SHA-256 fingerprint
- 0F:68:A8:95:37:FF:F1:63:0D:99:62:C8:56:4F:79:BD:9F:15:9B:41:00:69:45:8B:1E:CA:1C:63:35:39:A1:0D
- Serial
- 05146D6C06CF838CC14A9BDA20E56C8B26D3
subject_alt_names · 10
account.protonvpn.com
app.protonmail.ch
beta.protonmail.com
mail.protonmail.com
old.protonmail.com
pm.me
protonmail.ch
protonmail.com
protonvpn.com
secure.protonmail.com
certificate_chain · 2 certs
[ leaf ]protonmail.com
50 days left
issuer: R12
2026-03-13 → 2026-06-11
[ inter ]R12
325 days left
issuer: ISRG Root X1
2024-03-13 → 2027-03-12