SSL/TLS Certificate Lookup
Check a domain's SSL/TLS certificate — who issued it, when it expires, and whether the chain is trusted
theo-web.de
SSL/TLS Certificate
SSL/TLS Certificate for theo-web.de
Valid- Issued by (CA)
- Hellenic Academic and Research Institutions CA
- Subject
- lb2.cweb.univie.ac.at
- Valid from
- Sep 1, 2026
- Valid until
- Mar 19, 2027 (169 days remaining)
- Public key
- RSA 4096-bit
- Serial
- 438036CA514E090210BB5D8F40BB5D9B
- SHA-256 fingerprint
- 05:35:38:A4:8D:2D:FD:27:BF:53:84:12:E1:02:2B:C0:74:69:C6:3F:F0:B7:C6:97:7F:51:8C:F5:1E:A4:E2:61
- Chain
- GEANT TLS RSA 1 → HARICA TLS RSA Root CA 2021 → Hellenic Academic and Research Institutions RootCA 2015
Certificate Authority Authorization (CAA)
No CAA policy is published for this domain — any certificate authority may issue for it.
We've observed 1 previous certificate for this host. This certificate has been served since Sep 20, 2026.
Never get surprised by theo-web.de's certificate expiring
This is today's certificate. Turn on monitoring and we'll watch theo-web.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.
Free for your first domain: uptime, DNS, and certificate together. No credit card.