~/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 150 more days.
── output ─────
Issued to
www.kpn.com
Issued by
Sectigo Public Server Authentication CA DV R36
Valid from
2025-08-18
Valid until
2026-09-18 (150 days)
TLS version
TLSv1.3
Cipher
TLS_AES_128_GCM_SHA256
Key
RSA · 2048 bit
Signature
sha256WithRSAEncryption
Forward secrecy
yes
Self-signed
no
Must-staple
no
SHA-256 fingerprint
29:18:89:D4:83:D0:69:53:72:93:00:1F:D0:5D:B8:9B:5C:AC:69:17:4F:DB:97:76:65:5E:86:97:01:B1:3D:D8
Serial
10A63298E4E13DF3063C98E7ADBA5C37
subject_alt_names · 4
www.kpn.com kpn.com kpn.nl www.kpn.nl
certificate_chain · 2 certs
[ leaf ]www.kpn.com
150 days left
issuer: Sectigo Public Server Authentication CA DV R36
2025-08-18 → 2026-09-18
[ inter ]Sectigo Public Server Authentication CA DV R36
3622 days left
issuer: Sectigo Public Server Authentication Root R46
2021-03-22 → 2036-03-21
// Save kpn.com → we'll run this daily and alert on changes. /signup →