SSL/TLS Certificate Lookup
Check a domain's SSL/TLS certificate — who issued it, when it expires, and whether the chain is trusted
theorie-leren.nl
SSL/TLS Certificate
SSL/TLS Certificate for theorie-leren.nl
Valid- Issued by (CA)
- Sectigo Limited
- Subject
- theorie-leren.nl
- Valid from
- Oct 14, 2026
- Valid until
- Apr 30, 2027 (176 days remaining)
- Public key
- RSA 4096-bit
- Serial
- 8236A763942B4D8286252B97BBA2A7B3
- SHA-256 fingerprint
- A4:C8:E2:CD:4D:E3:AC:47:6E:71:CB:1E:97:FF:12:F5:DC:CE:9E:B3:27:D5:71:0D:68:CA:A8:1C:3D:D5:D0:FE
- Chain
- Sectigo Public Server Authentication CA DV R36 → Sectigo Public Server Authentication Root R46 → USERTrust RSA Certification Authority
Certificate Authority Authorization (CAA)
The serving CA (Sectigo Limited) is authorized by this domain's CAA records (letsencrypt.org, sectigo.com).
We've observed 1 previous certificate for this host. This certificate has been served since Oct 27, 2026.
Never get surprised by theorie-leren.nl's certificate expiring
This is today's certificate. Turn on monitoring and we'll watch theorie-leren.nl 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, CNAME, TXT 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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