SSL/TLS Certificate Lookup
Check a domain's SSL/TLS certificate — who issued it, when it expires, and whether the chain is trusted
jef-site.or.jp
SSL/TLS Certificate
SSL/TLS Certificate for jef-site.or.jp
Valid- Issued by (CA)
- Let's Encrypt
- Subject
- www.jef-site.or.jp
- Valid from
- Jul 28, 2026
- Valid until
- Oct 26, 2026 (78 days remaining)
- Public key
- RSA 2048-bit
- Serial
- 0634E0B5CE6261AD7C60E4ED15160F772F62
- SHA-256 fingerprint
- 5C:3B:AF:7A:45:68:79:24:86:D4:F0:DD:D5:E1:2C:71:C8:45:19:1A:E6:A5:C8:6C:0D:D1:6E:4F:BB:2C:9D:4F
- Chain
- YR2 → 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 jef-site.or.jp's certificate expiring
This is today's certificate. Turn on monitoring and we'll watch jef-site.or.jp continuously, notifying you the moment anything moves across all three signals:
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, 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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