Censys Data Collection


Censys collects data about hosts and websites on the Internet through regular scans of the public IPv4 address space and the Alexa Top Million Domains. We validate, transform, and annotate this data with additional metadata (e.g., device model and geographic location), which we use to maintain the Censys indexes. We perform these scans from the University of Michigan using several tools from the ZMap Project, including ZMap, ZGrab, ZTag, and ZDNS.

Primary Datasets


We publish daily snapshots of what we know about each host, website, and certificate. These datasets contain structured, non-ephemeral JSON records that identify a host's configuration—similar to what is available in the search interface.



Regular IPv4 Scans


We perform the following regular scans of the IPv4 address space:


Regular Web (Alexa Top Million) Scans


We perform the following regular scans of the Alexa Top Million domains:


Other Internet Scans


These are other scans that we've performed in the past or complete on an ad-hoc basis: