SSL/TLS Certificate Lookup
Check a domain's SSL/TLS certificate — who issued it, when it expires, and whether the chain is trusted
y-kenkou.or.jp
SSL/TLS Certificate
SSL/TLS Certificate for y-kenkou.or.jp
Valid- Issued by (CA)
- Let's Encrypt
- Subject
- www.y-kenkou.or.jp
- Valid from
- Oct 8, 2026
- Valid until
- Jan 6, 2027 (64 days remaining)
- Public key
- RSA 2048-bit
- Serial
- 06F20246B2FD6E1D77BDF4A26B8478FFE920
- SHA-256 fingerprint
- 42:58:3F:68:34:39:72:6B:36:96:05:D4:E1:64:40:04:32:6D:72:92:B1:EB:70:87:2F:3A:80:7B:18:87:15:35
- Chain
- YR1 → Root YR → ISRG Root X1
Certificate Authority Authorization (CAA)
No CAA policy is published for this domain — any certificate authority may issue for it.
Never get surprised by y-kenkou.or.jp's certificate expiring
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Uptime
We visit the site from multiple regions worldwide and email you within minutes if it goes down, with a per-region breakdown so a real outage stands out from a regional blip.
DNS changes
We watch NS, MX, CAA, CNAME, TXT 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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