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 wisc.edu

Valid
Issued by (CA)
Let's Encrypt
Subject
wisc.edu
Valid from
Aug 3, 2026
Valid until
Nov 1, 2026 (59 days remaining)
Public key
RSA 2048-bit
Serial
05F13CB2CE942AA5A0AA91A0CFC3B6D3265B
SHA-256 fingerprint
CC:16:6C:9B:6A:4B:CC:8A:6B:B8:48:E6:3C:C6:DF:53:69:4D:D5:24:2B:AD:99:D4:64:F2:2E:FF:9C:F5:88:47
Chain
YR2 → Root YR → ISRG Root X1
Subject Alternative Names (1)
wisc.edu

Certificate Authority Authorization (CAA)

No CAA policy is published for this domain — any certificate authority may issue for it.

We've observed 1 previous certificate for this host. This certificate has been served since Aug 13, 2026.

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This is today's certificate. Turn on monitoring and we'll watch wisc.edu continuously, notifying you the moment anything moves across all three signals:

Uptime

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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.

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