SSL/TLS Certificate Lookup

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

SSL/TLS Certificate for petruska.jp

Valid
Issued by (CA)
Let's Encrypt
Subject
petruska.jp
Valid from
Aug 1, 2026
Valid until
Oct 30, 2026 (52 days remaining)
Public key
RSA 2048-bit
Serial
05332440B505A0BDA78CC93913155622AE50
SHA-256 fingerprint
42:BE:18:91:71:D4:39:61:D6:AF:19:94:D8:B9:9E:5B:25:F9:B4:50:8A:06:CE:31:07:28:74:2D:A9:10:97:C3
Chain
YR2 → Root YR → ISRG Root X1
Subject Alternative Names (2)
petruska.jp, www.petruska.jp

Certificate Authority Authorization (CAA)

No CAA policy is published for this domain — any certificate authority may issue for it.

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Uptime

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DNS changes

We watch NS, MX, CAA, DNSSEC, CNAME and A/AAAA records, and identify the host, network, and ASN behind them, so a real migration or hijack stands out from routine noise.

TLS certificate

We warn you 30, 14, 7, and 1 days before it expires, and flag it if the issuing authority changes or the certificate is unexpectedly replaced.

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