~/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 64 more days.
── output ─────
- Issued to
- o2.de
- Issued by
- WE1
- Valid from
- 2026-03-26
- Valid until
- 2026-06-25 (64 days)
- TLS version
- TLSv1.3
- Cipher
- TLS_AES_256_GCM_SHA384
- Key
- EC (prime256v1) · 256 bit
- Signature
- ecdsa-with-SHA256
- Forward secrecy
- yes
- Self-signed
- no
- Must-staple
- no
- SHA-256 fingerprint
- 5D:AD:53:E8:C8:04:E0:E8:01:91:4A:A1:4E:2F:5F:D6:7C:7A:A6:42:73:9E:2D:64:AB:77:F1:FC:B3:6C:97:28
- Serial
- 6CB3EC928501BF8F0E60EF8374E48104
subject_alt_names · 2
o2.de
*.o2.de
certificate_chain · 3 certs
[ leaf ]o2.de
64 days left
issuer: WE1
2026-03-26 → 2026-06-25
[ inter ]WE1
1035 days left
issuer: GTS Root R4
2023-12-13 → 2029-02-20
[ inter ]GTS Root R4
646 days left
issuer: GlobalSign Root CA
2023-11-15 → 2028-01-28