SSL/TLS Certificate Lookup
Check a domain's SSL/TLS certificate — who issued it, when it expires, and whether the chain is trusted
f-tekou.co.jp
SSL/TLS Certificate
SSL/TLS Certificate for f-tekou.co.jp
Valid- Issued by (CA)
- Let's Encrypt
- Subject
- f-tekou.co.jp
- Valid from
- Aug 20, 2026
- Valid until
- Nov 18, 2026 (71 days remaining)
- Public key
- RSA 2048-bit
- Serial
- 0634A099C5FA6953A109A7F099018E2C2E07
- SHA-256 fingerprint
- 2C:0B:39:50:F2:BA:70:92:FD:01:4A:4F:BB:F9:9E:1C:57:E3:22:02:0F:79:0C:AF:DD:87:66:B6:1B:CF:EC:22
- 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.
This certificate has been served since Sep 3, 2026.
Never get surprised by f-tekou.co.jp's certificate expiring
This is today's certificate. Turn on monitoring and we'll watch f-tekou.co.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.
Free for your first domain: uptime, DNS, and certificate together. No credit card.