Infrastructure & Network Reconnaissance
Censys
Search engine for internet-facing hosts, certs, and services.
Censys is a search engine designed to discover and analyze internet-facing hosts, certificates, and services. It enables researchers to map the attack surface of organizations by identifying exposed assets and verifying the validity of digital certificates. This tool is commonly used for infrastructure reconnaissance and vulnerability assessment in legitimate security investigations.
Dual-use tool. This is capable of legitimate research (journalism, security, due diligence) and of harassment or stalking. Listing it here is not an endorsement of either use.
Official site: https://censys.io
Last verified 2026-08-30.