SSL/TLS Certificate Lookup
Check a domain's SSL/TLS certificate — who issued it, when it expires, and whether the chain is trusted
jonathanzittrain.com
SSL/TLS Certificate
We don't have a current record for jonathanzittrain.com, but we hold 1 historical WHOIS/RDAP snapshot of it from 2012. See its domain history.
SSL/TLS Certificate for jonathanzittrain.com
No TLS certificate could be retrieved (connect ECONNREFUSED 217.70.184.38:443).
The domain may not serve HTTPS, may be unreachable, or may not present a certificate on port 443. You can still review its DNS records.
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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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