SSL/TLS Certificate Lookup

Check a domain's SSL/TLS certificate — who issued it, when it expires, and whether the chain is trusted

cassis.cz

SSL/TLS Certificate

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SSL/TLS Certificate for cassis.cz

Valid
Issued by (CA)
Let's Encrypt
Subject
cassis.cz
Valid from
Jun 6, 2026
Valid until
Sep 4, 2026 (44 days remaining)
Public key
RSA 4096-bit
Serial
05541BFBFD58202F569DE9B7FF31C56A7010
SHA-256 fingerprint
81:63:BC:78:1C:E9:84:A9:31:33:9F:72:29:47:FC:41:E4:C3:47:11:40:AA:25:7F:24:90:25:BD:36:C0:A9:12
Chain
YR2 → Root YR → ISRG Root X1
Subject Alternative Names (2)
cassis.cz, www.cassis.cz

Certificate Authority Authorization (CAA)

The serving CA (Let's Encrypt) is authorized by this domain's CAA records (letsencrypt.org).