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 desy.de
Valid- Issued by (CA)
- Hellenic Academic and Research Institutions CA
- Subject
- www.desy.de
- Valid from
- Nov 8, 2025
- Valid until
- Nov 8, 2026 (107 days remaining)
- Public key
- RSA 4096-bit
- Serial
- 18251D5288A6D7E48DABC983044603F4
- SHA-256 fingerprint
- 82:99:FC:66:37:62:4A:A4:8D:97:35:C5:60:AA:CD:15:0F:C4:0B:D4:B3:D2:2F:54:1A:42:6D:2E:86:8B:5E:15
- Chain
- GEANT TLS RSA 1 → HARICA TLS RSA Root CA 2021 → Hellenic Academic and Research Institutions RootCA 2015
Certificate Authority Authorization (CAA)
CAA restricts issuance to amazon.com, globalsign.com, harica.gr, letsencrypt.org, pki.dfn.de, sectigo.com; we couldn't map the serving CA (Hellenic Academic and Research Institutions CA) to one of these identifiers.
This certificate has been served since Jul 23, 2026.
Never get surprised by desy.de's certificate expiring
This is today's certificate. Turn on monitoring and we'll watch desy.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.