SSL/TLS Certificate Lookup
Check a domain's SSL/TLS certificate — who issued it, when it expires, and whether the chain is trusted
u-koreit.co.kr
SSL/TLS Certificate
SSL/TLS Certificate for u-koreit.co.kr
Expired- Issued by (CA)
- Let's Encrypt
- Subject
- www.energyjobfair.co.kr
- Valid from
- Jun 16, 2026
- Valid until
- Sep 14, 2026 (expired 36 days ago)
- Public key
- EC 256-bit
- Serial
- 05BB5BDDFC1F1328DBD76299FBCD9E86494D
- SHA-256 fingerprint
- 83:73:BC:F8:66:48:F9:90:04:C0:CF:10:B1:C1:A8:02:33:E6:49:73:29:F5:A4:7E:DC:A0:1A:2A:C8:06:D1:B0
- Chain
- YE1 → Root YE → ISRG Root X2 → 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 Oct 5, 2026.
Never get surprised by u-koreit.co.kr's certificate expiring
This is today's certificate. Turn on monitoring and we'll watch u-koreit.co.kr 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.
Free for your first domain: uptime, DNS, and certificate together. No credit card.