Kali Linux Documentation
Kali Linux is OffSec's free, Debian-based Linux distribution preloaded with hundreds of security testing tools, and its official documentation covers installing it as a virtual machine, on bare metal, in the cloud, on ARM devices or inside a container. Installing it inside a virtual machine is by far the most common and safest starting point for learning, keeping the tool-heavy distribution isolated from your everyday operating system. The documentation is free and kept current with each Kali release.
Guide
Other
OffSec
Beginner
Free
What it is
Kali Linux is a Debian-based Linux distribution maintained by OffSec, purpose-built for penetration testing and security research, with hundreds of tools such as Nmap, Wireshark, Burp Suite and many others preinstalled and organised by category. The official documentation at kali.org/docs covers every supported way to install and run it: virtual machines, bare-metal installation, USB persistence, ARM single-board computers, WSL, containers, cloud platforms and the NetHunter mobile builds.
Installing it as a virtual machine
For most learners, running Kali inside a virtual machine on VMware, VirtualBox, Hyper-V or a similar hypervisor is the recommended starting point. Kali publishes ready-made virtual machine images for the most common hypervisors, which avoids a full manual installation and keeps the security-testing environment cleanly separated from your host operating system, an important safety boundary when running tools that can affect a network. The documentation walks through importing these images and the small amount of configuration each hypervisor needs.
How to use it
Start with the virtualisation section for your chosen hypervisor, import the appropriate image, and confirm networking works as expected before installing anything else. From there, the general use and tools sections of the documentation explain how Kali organises its toolset by category, and the troubleshooting section covers common issues like display resolution or networking quirks inside a virtual machine.
Free versus paid
Kali Linux and its documentation are completely free, distributed as open source and free-of-charge downloads with no licence fee or paid tier.
Prerequisites
Basic comfort installing and using a Linux desktop environment is helpful, though the documentation assumes very little prior Kali-specific knowledge. Understanding your chosen hypervisor's basics, such as how to configure networking mode, is worth doing before starting.
Using it responsibly
Kali bundles many tools that are only legal to use with permission. Only test systems you own or are explicitly authorised to test: your own lab, a CTF, or an in-scope bug bounty programme. Having the tools installed is not itself authorisation to use them against anything else, and a network you merely have access to, such as a university or workplace network, is not yours to test.
Common questions
Do I need a powerful computer to run it in a VM? A modest allocation of a few gigabytes of memory and a couple of CPU cores is enough for learning.
Is Kali good as a daily-use desktop operating system? It is purpose-built for security testing rather than general use, so most people run it as a dedicated lab environment rather than an everyday desktop.
Does installing Kali make someone a hacker? No, the distribution is just a curated toolset; the skill comes from learning what each tool does and when its use is appropriate and authorised.
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