Best Open-Source Network Scanners 2026: 6 Options Compared

A network scanner can mean three different things: discovering which devices are on your network, finding open ports on a host, or looking for known vulnerabilities. Angry IP Scanner is the friendly choice for the first job, with a graphical window that lists live hosts and open ports on a local network. Masscan, ZMap and RustScan are built for speed. Masscan and ZMap can sweep enormous address ranges, so they suit security researchers and large networks, and RustScan quickly finds open ports on a single host. Greenbone, the engine behind OpenVAS, goes further and checks for known vulnerabilities, though its free community feed lacks the enterprise coverage and API access of the paid product. Nuclei runs community templates against web apps and services to find specific weaknesses. The widely used Nmap is source-available under its own licence and is not counted as open source here, so it is omitted from the picks. Permission matters: scan only networks and systems you own or are authorised to test, because unauthorised scanning can break laws and get your address blocked. Fast scanners can also overload old equipment, so lower the rate on small or fragile networks. For a home network, a graphical scanner is plenty. Reach for a vulnerability scanner when you have servers that face the internet.

Angry IP Scanner

GPL-2.0 graphical scanner that lists live hosts and open ports on a local network. The easiest way to see what is on your LAN.

Price: Free (Free and open source; no installation required) (Angry IP Scanner pricing, checked 2026-10-24).

Platforms and license: Windows, macOS, Linux. Free and open source (license not named on the home page) (open source) (license source).

Best for: Seeing what is on a home network.

RustScan

GPL-3.0 fast port scanner written in Rust. Good for finding open ports on a host quickly.

Price: Free (Free and open source) (RustScan pricing, checked 2026-10-24).

Platforms and license: Linux, macOS, Docker. GPL-3.0 (open source) (license source).

Project activity: 20.6k GitHub stars · latest release 2.4.1 (Feb 23, 2025) · last commit Oct 20, 2026

Best for: Quick single-host port scans.

Masscan

AGPL-3.0 high-speed TCP port scanner that can sweep large ranges. Powerful enough to overwhelm small networks, so tune the rate.

Price: Free (Free open source) (Masscan pricing, checked 2026-10-24).

Platforms and license: Linux, macOS, Windows. AGPL-3.0 (open source) (license source).

Project activity: 26.1k GitHub stars · latest release 1.3.2 (Jan 31, 2021) · last commit Oct 5, 2026

Best for: Large address ranges.

Worth knowing: High-speed TCP port scanner; scan only networks you are allowed to test.

ZMap

Apache-2.0 scanner designed for very large, internet-scale probing with single-packet probes. Aimed at researchers, and overkill for a home network.

Price: Free (Free open source) (ZMap pricing, checked 2026-10-24).

Platforms and license: Linux. Apache-2.0 (open source) (license source).

Project activity: 6.4k GitHub stars · latest release v4.4.0 (May 29, 2026) · last commit Oct 25, 2026

Best for: Research-scale scanning.

Worth knowing: Single-packet-probe scanner built for very large address ranges; scan only networks you are allowed to test.

Greenbone (OpenVAS)

Greenbone Community uses GPL-2.0 and AGPL-3.0 components for vulnerability scanning. It is free but lacks enterprise coverage, API access and support.

Price: Free (OPENVAS FREE is free of charge; it lacks enterprise-grade software coverage, automatic scan initialization, alerts, API access and support) (Greenbone (OpenVAS) pricing, checked 2026-10-22).

Platforms and license: Linux, Docker. GPL-2.0 (openvas-scanner); AGPL-3.0 (gvmd, GSA) (open source) (license source).

Project activity: 4.9k GitHub stars · latest release v23.52.6 (Oct 27, 2026) · last commit Oct 27, 2026

Best for: Finding known vulnerabilities.

Nuclei

MIT template-based scanner for web apps, networks and cloud. Free, and driven by community templates.

Price: Free (Free open-source template-based scanner) (Nuclei pricing, checked 2026-10-22).

Platforms and license: macOS, Windows, Linux. MIT (open source) (license source).

Project activity: 32.4k GitHub stars · latest release v3.11.1 (Aug 8, 2026) · last commit Oct 27, 2026

Best for: Checking for specific known weaknesses.

Worth knowing: Template-driven scanning of web apps, networks and cloud; not an authenticated host-patch auditor.

Which one to pick

• You want to see devices on your home Wi-Fi: Angry IP Scanner
• You need open ports on one server fast: RustScan
• You scan thousands of addresses: Masscan
• You want to check servers for known vulnerabilities: Greenbone (OpenVAS)