How to use the Nmap Command Generator
- 1. Enter targetsAn IP, range, network or hostname on a network you're allowed to scan.
- 2. Choose the scanScan type, ports, service and OS detection, timing and output format.
- 3. Build commandCopy the command and read what each option does.
Choosing a scan
Start with host discovery (-sn) to see which devices are up without touching their ports. A SYN scan (-sS) is the usual port scan: fast, and it never completes connections, but it needs administrator rights. Without them, use a connect scan (-sT). UDP (-sU) finds services like DNS and SNMP but is slow. -sV identifies the software and version on each open port, -sC runs Nmap's default scripts for extra details, and -O guesses the operating system. Everything is calculated in your browser; nothing you enter is uploaded.
The generator adds sudo only when an option needs it, refuses text that isn't a target (so nothing else can be slipped into the command), and leaves out firewall-evasion options on purpose.
Worked example
The defaults build sudo nmap -sS -F -sV -n --open -T4 -v -oA scan-lan 192.168.1.0/24: a SYN scan of the 100 most common ports on every host in the 192.168.1.0/24 network, with version detection, no DNS lookups, only open ports shown, aggressive timing, live progress, and results saved as scan-lan.nmap, scan-lan.xml and scan-lan.gnmap.
Scan responsibly
- Scan only networks you own or have written permission to test; unauthorised scanning can break the law, including India's IT Act.
- Use -T2 or -T3 on production and shared networks.
- The XML output imports into many tools and reports.
Frequently asked questions
Do I need root?
For SYN, UDP and OS detection, yes; the tool adds sudo for those. Connect scans and host discovery work without it (discovery is more limited).
Why are some hosts missing?
Many block ping. Tick 'Skip host discovery' (-Pn) to scan them anyway, at the cost of speed.
Is the Nmap command generator free?
Yes. You can open the Nmap command generator and use every option without signing up. When you build a command for the first time, we ask once for your name and WhatsApp number; after that it, and every other Uncodemy tool, opens straight away.