USB boot has been possible since the Raspberry Pi 2 Model B (v1.2), but it has only become really worthwhile with the Pi 4. Here is some information, tips, tricks and opinions explaining why and how.

Early versions of the Raspberry Pi could only boot from SD cards, but newer ones can boot from any USB device, like an external drive or USB stick. Here's how.

Raspberry Pi Foundation is almost ready to deliver a fix for Raspberry Pi 4's lack of support for USB mass storage boot.

Requirements The Raspberry Pi Foundation, the group behind the device, recommends using a Micro-USB power supply from a reputable company that can produce 1.2A (1,200mA) at 5V.

You can now boot the Raspberry Pi 3 from just about anything. The documentation for these new boot modes goes over the process of how to put an image on a USB thumb drive.