Booting Kali Linux from a USB drive can be very useful for trying out the operating system without installing it or for using it on computers where you can't install it. Kali Linux is a Debian-based distribution focused on security and penetration testing.
Booting Kali Linux as a "live" operating system from a USB allows you to use all the included penetration testing and security tools without making any changes to the computer. It's also convenient for using Kali on multiple machines or bringing your customized Kali setup with you.
What You'll Need
A 4GB or larger USB flash drive
The Kali Linux ISO file
Rufus or Etcher for Windows / Startup Disk Creator for Linux
Step 1 - Download Kali Linux
First, download the latest Kali Linux ISO image from the official website. Choose the standard Kali image, not one of the specialized versions.
Step 2 - Install the ISO on the USB Drive
On Windows
On Windows, the easiest way to copy the Kali ISO to a USB is to use the utility Rufus. Simply insert your drive, launch Rufus, select your Kali ISO, and flash it.
The free Etcher app works similarly for a very simple USB installation process.
On Linux
On Linux, you can use the Startup Disk Creator utility. Insert your drive, launch Startup Disk Creator, select the ISO, your USB drive, and click Make Startup Disk.
Step 3 - Configure the BIOS
To boot Kali Linux from the USB drive, you'll need to configure the BIOS. Restart your computer and enter the BIOS setup utility, usually by pressing F2, F10 or Delete during startup. Adjust the boot order and move "USB Drive" or your flash drive name to the top.
This tells your computer to first try booting from the USB ports before the main hard drive.
Step 4 - Boot Into Kali Linux
With the USB drive inserted and BIOS configured, restart your computer again.
It will now load files from the USB instead of the hard drive and boot directly into Kali Linux. Welcome to Kali Linux!
The default Kali login credentials are:
Username: root
Password: toor
Now you can use Kali without installing it or making any changes to your system. And since everything saves onto the USB drive, you can use your custom Kali setup on any computer that supports booting from USB.
Summary of Steps
Download the Kali Linux ISO image
Use Rufus or Etcher to copy the ISO onto the USB drive
Change the BIOS settings to prioritize USB booting
Reboot and Kali Linux will launch from the USB
Booting Kali Linux from a flash drive makes trying out penetration testing tools easy. It also enables you to carry a portable Kali setup or use it safely without modifications to your computers. With the process above, you can be up and running with a bootable USB Kali install in just a few minutes.