SSL/TLS Certificate Lookup
Check a domain's SSL/TLS certificate — who issued it, when it expires, and whether the chain is trusted
dr-seitner.com
SSL/TLS Certificate
SSL/TLS Certificate for dr-seitner.com
Valid- Issued by (CA)
- Let's Encrypt
- Subject
- dr-seitner.com
- Valid from
- Jul 13, 2026
- Valid until
- Oct 11, 2026 (26 days remaining)
- Public key
- RSA 2048-bit
- Serial
- 0509F726300EB3DD38A5D75FC77174555080
- SHA-256 fingerprint
- B2:65:46:AC:F1:E7:47:1E:B4:2B:5B:B1:D4:41:EF:33:EE:EC:E2:B4:C5:A4:6B:91:33:6A:3B:76:8C:69:63:68
- 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 dr-seitner.com's certificate expiring
This is today's certificate. Turn on monitoring and we'll watch dr-seitner.com 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.