Port scanning

Which network services are listening?

Port scanners send packets to hosts and report which ports answer. This is active by definition: run it only against hosts you own or are authorised to test.

Listed alphabetically. The order is not a ranking.

• MASSCANActive

  Asynchronous Internet-scale port scanner with nmap-like flags, its own TCP/IP stack and optional banner grabbing on common protocols.

  26k stars · last push October 5, 2026 · 1.3.2 · AGPL-3.0

• NaabuPassive and active modes

  Go port scanner doing fast SYN, CONNECT and UDP scans across hosts, CIDRs and ASNs, with CDN exclusion and Nmap hand-off.

  6.4k stars · last push November 9, 2026 · v2.7.0 · MIT

• NmapActive

  Network scanner that discovers live hosts, open ports, service versions and operating systems, with a Lua scripting engine for extra checks.

  14k stars · last push November 9, 2026 · LicenseRef-NPSL