SSL/TLS Certificate Lookup
Check a domain's SSL/TLS certificate — who issued it, when it expires, and whether the chain is trusted
cosmos-school.com.tw
SSL/TLS Certificate
SSL/TLS Certificate for cosmos-school.com.tw
Valid- Issued by (CA)
- Sectigo Limited
- Subject
- www.cosmos-school.com.tw
- Valid from
- Jan 21, 2026
- Valid until
- Feb 21, 2027 (206 days remaining)
- Public key
- RSA 2048-bit
- Serial
- 5B5B0210C5C1C9BCA0783C92B12BABE1
- SHA-256 fingerprint
- 76:60:C3:01:DC:11:D8:79:69:6C:05:8B:04:28:57:12:C2:26:BE:D8:3A:E5:59:2E:D7:6D:5A:F4:02:13:52:94
- Chain
- Sectigo Public Server Authentication CA DV R36 → Sectigo Public Server Authentication Root R46
Certificate Authority Authorization (CAA)
No CAA policy is published for this domain — any certificate authority may issue for it.
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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.
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