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 wopen.de
Valid- Issued by (CA)
- Let's Encrypt
- Subject
- buecher-wenner.de
- Valid from
- Oct 8, 2026
- Valid until
- Jan 6, 2027 (66 days remaining)
- Public key
- EC 256-bit
- Serial
- 052251C804B70B126867FBE507990E6F0D59
- SHA-256 fingerprint
- 04:A5:EE:3A:1E:D7:D5:92:23:6E:4A:4C:57:57:B0:49:59:E0:4F:A7:BC:CA:48:05:26:25:9D:BE:67:B3:80:37
- Chain
- YE2 → Root YE → ISRG Root X2 → ISRG Root X1
Certificate Authority Authorization (CAA)
No CAA policy is published for this domain — any certificate authority may issue for it.
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This is today's certificate. Turn on monitoring and we'll watch wopen.de continuously, notifying you the moment anything moves across all three signals:
Uptime
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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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