~/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 138 more days.
── output ─────
Issued to
*.strato.de
Issued by
Sectigo Public Server Authentication CA OV R36
Valid from
2025-08-06
Valid until
2026-09-06 (138 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
83:4D:D2:F7:AD:8E:2F:7D:67:E6:84:E4:F1:76:83:39:66:3E:51:84:44:DF:2F:A6:44:FC:69:A2:7F:BF:E0:20
Serial
421C0942E9A468A9B8733962A53D30E5
subject_alt_names · 2
*.strato.de strato.de
certificate_chain · 3 certs
[ leaf ]*.strato.de
138 days left
issuer: Sectigo Public Server Authentication CA OV R36
2025-08-06 → 2026-09-06
[ inter ]Sectigo Public Server Authentication CA OV R36
3622 days left
issuer: Sectigo Public Server Authentication Root R46
2021-03-22 → 2036-03-21
[ inter ]Sectigo Public Server Authentication Root R46
4290 days left
issuer: USERTrust RSA Certification Authority
2021-03-22 → 2038-01-18
// Save strato.de → we'll run this daily and alert on changes. /signup →