Subfinder
Fast passive subdomain discovery tool that enumerates valid subdomains for a domain.
Subfinder is an open-source subdomain discovery tool that returns valid subdomains for a domain using passive online sources. It has a modular architecture, supports JSON, file and stdout output, and can be used with STDIN and STDOUT in command-line workflows.
Official site: https://github.com/projectdiscovery/subfinder
Source: https://github.com/projectdiscovery/subfinder
Last verified 2026-10-06.
Description rewritten from the vendor's own pages and checked against them. How entries are checked.