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 ysb.kr
Expired- Issued by (CA)
- Let's Encrypt
- Subject
- ysb.kr
- Valid from
- Mar 4, 2026
- Valid until
- Jun 2, 2026 (expired 83 days ago)
- Public key
- EC 256-bit
- Serial
- 0639BBEC46020EC94E59AC6F31A74E486AF7
- SHA-256 fingerprint
- 01:F1:A7:C6:92:29:A5:4A:6C:F4:E3:DE:29:3C:EF:3E:08:01:50:19:94:D2:76:2D:E3:83:96:9B:94:4D:50:51
- Chain
- E8 → ISRG Root X1
Certificate Authority Authorization (CAA)
No CAA policy is published for this domain — any certificate authority may issue for it.
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Uptime
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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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