SSL/TLS Certificate Lookup
Check a domain's SSL/TLS certificate — who issued it, when it expires, and whether the chain is trusted
tg-group.ac.jp
SSL/TLS Certificate
SSL/TLS Certificate for tg-group.ac.jp
Valid- Issued by (CA)
- Let's Encrypt
- Subject
- www.tg-group.ac.jp
- Valid from
- Oct 22, 2026
- Valid until
- Jan 20, 2027 (71 days remaining)
- Public key
- RSA 2048-bit
- Serial
- 059219953E84B8BA6458CAFD49884A59175A
- SHA-256 fingerprint
- CD:5E:C7:2F:11:9A:83:4C:57:F7:AE:3A:A0:92:BC:0B:FF:84:21:4F:D1:87:4C:8C:12:8C:8F:99:54:90:2C:48
- 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 tg-group.ac.jp's certificate expiring
This is today's certificate. Turn on monitoring and we'll watch tg-group.ac.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, 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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