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 cu-it.de
Valid- Issued by (CA)
- Let's Encrypt
- Subject
- www.cu-it.de
- Valid from
- Jul 9, 2026
- Valid until
- Oct 7, 2026 (75 days remaining)
- Public key
- RSA 4096-bit
- Serial
- 05E504AE5420FBE7D1C213AB0DF45412A3C9
- SHA-256 fingerprint
- 91:1C:98:F3:B7:4B:35:98:04:E6:81:E6:45:E7:C1:2B:AC:E5:F6:46:12:7D:BE:2A:72:84:DD:56:A7:51:38:F9
- Chain
- YR2 → Root YR → ISRG Root X1
Certificate Authority Authorization (CAA)
The serving CA (Let's Encrypt) is authorized by this domain's CAA records (letsencrypt.org).
Never get surprised by cu-it.de's certificate expiring
This is today's certificate. Turn on monitoring and we'll watch cu-it.de 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.
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