SSL/TLS Certificate Lookup

Check a domain's SSL/TLS certificate — who issued it, when it expires, and whether the chain is trusted

SSL/TLS Certificate for f-sakai.com

Valid
Issued by (CA)
Let's Encrypt
Subject
f-sakai.com
Valid from
Aug 15, 2026
Valid until
Nov 13, 2026 (89 days remaining)
Public key
RSA 2048-bit
Serial
06C659E165E2C23643B38DCA82C02AE366D0
SHA-256 fingerprint
ED:6A:A3:34:B0:55:95:73:D1:CF:24:BE:3D:E3:01:47:EF:AB:8B:02:B0:A0:EB:3A:84:CA:04:FD:71:04:CB:59
Chain
YR1 → Root YR → ISRG Root X1
Subject Alternative Names (2)
f-sakai.com, www.f-sakai.com

Certificate Authority Authorization (CAA)

No CAA policy is published for this domain — any certificate authority may issue for it.

Never get surprised by f-sakai.com's certificate expiring

This is today's certificate. Turn on monitoring and we'll watch f-sakai.com 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.

Monitor this certificate free

Free for your first domain: uptime, DNS, and certificate together. No credit card.