Infrastructure & Network Reconnaissance
Censys
Search engine for internet-facing hosts, certs, and services.
Censys says its Platform delivers real-time visibility and actionable intelligence needed to accelerate triage and manage Internet exposure. For exposure management, the page describes discovering unknown assets and continuously monitoring an external attack surface to reduce exposure.
Dual-use tool. This tool can be used for research and investigation, and also to find, track or identify people without their consent. Listing it here is not an endorsement of either use.
Privacy note. Censys scans every public IPv4 address and popular domain names and makes the results searchable, so a server, device or certificate you run that is reachable from the internet can appear in its results. Censys's opt-out page (docs.censys.com/docs/opt-out-of-data-collection) says to opt out you configure your firewall to drop traffic from the subnets and ASNs Censys scans from, and warns that doing so may stop you receiving its security alerts. The page says blocking does not remove historical data.
Official site: https://censys.io
Last verified 2026-10-12.
Description rewritten from the vendor's own pages and checked against them. How entries are checked.