subfinder
Subdomain discovery tool
web-scanningRed Team
Toolweb-scanningredLinuxKali LinuxPlatforms: Linux · Last verified September 6, 2026
This package contains a subdomain discovery tool that discovers valid subdomains for websites by using passive online sources. It has a simple modular architecture and is optimized for speed. subfinder is built for doing one thing only - passive subdomain enumeration, and it does that very well.
Only use this tool against systems you own or are explicitly authorized to test — see the disclaimer.
Getting started
Install on Kali Linux with `sudo apt install subfinder`. See the official Kali tool page and upstream homepage linked above for full usage and configuration details.
