SSL/TLS Certificate Lookup
Check a domain's SSL/TLS certificate — who issued it, when it expires, and whether the chain is trusted
it-potsdam.org
SSL/TLS Certificate
SSL/TLS Certificate for it-potsdam.org
Expired- Issued by (CA)
- Let's Encrypt
- Subject
- www.abc.krieewelsch.de
- Valid from
- Jun 24, 2025
- Valid until
- Sep 22, 2025 (expired 375 days ago)
- Public key
- RSA 2048-bit
- Serial
- 06A2C6AB74AA1FA7669DDED792A0FBE26161
- SHA-256 fingerprint
- E0:0A:BA:D4:AD:E5:F2:B9:25:9F:5A:7D:57:FC:3B:95:74:3A:5B:3E:F3:39:07:B9:72:AC:C0:24:C8:3F:13:AB
- Chain
- R10 → ISRG Root X1
Certificate Authority Authorization (CAA)
No CAA policy is published for this domain — any certificate authority may issue for it.
This certificate has been served since Sep 16, 2026.
Never get surprised by it-potsdam.org's certificate expiring
This is today's certificate. Turn on monitoring and we'll watch it-potsdam.org 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.