SSL/TLS Certificate Lookup
Check a domain's SSL/TLS certificate — who issued it, when it expires, and whether the chain is trusted
koa-ref.co.jp
SSL/TLS Certificate
SSL/TLS Certificate for koa-ref.co.jp
Valid- Issued by (CA)
- DigiCert Inc
- Subject
- www.koa-ref.co.jp
- Valid from
- Dec 22, 2025
- Valid until
- Dec 29, 2026 (156 days remaining)
- Public key
- RSA 2048-bit
- Serial
- 0A40D1AAB92589203A97C193B26B29FC
- SHA-256 fingerprint
- E1:09:56:19:DD:47:87:E8:21:01:1C:6C:1F:F6:E6:17:0B:6E:83:53:29:3A:5D:09:BB:F4:A6:E7:8D:E3:94:58
- Chain
- RapidSSL TLS RSA CA G1 → DigiCert Global Root G2
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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