~/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
costco.com
Issued by
DigiCert Global G3 TLS ECC SHA384 2020 CA1
Valid from
2025-09-04
Valid until
2026-09-06 (138 days)
TLS version
TLSv1.3
Cipher
TLS_AES_256_GCM_SHA384
Key
EC (prime256v1) · 256 bit
Signature
ecdsa-with-SHA384
Forward secrecy
yes
Self-signed
no
Must-staple
no
SHA-256 fingerprint
4B:FF:F7:23:E5:C7:C3:8A:3A:9E:A8:66:5D:BB:47:3A:C5:9B:86:D9:85:9E:B1:E7:23:26:6C:22:27:87:65:BA
Serial
020818F2B5130A6F93450D13D4755597
subject_alt_names · 2
costco.com www.costco.com
certificate_chain · 2 certs
[ leaf ]costco.com
138 days left
issuer: DigiCert Global G3 TLS ECC SHA384 2020 CA1
2025-09-04 → 2026-09-06
[ inter ]DigiCert Global G3 TLS ECC SHA384 2020 CA1
1818 days left
issuer: DigiCert Global Root G3
2021-04-14 → 2031-04-13
// Save costco.com → we'll run this daily and alert on changes. /signup →