If you have hacked your 3DS in the past, or you purchased your 3DS second-hand, it is possible that your console already has custom firmware. You should [check for CFW](checking-for-cfw) before proceeding.
Different device models, versions, and regions will require different steps to achieve the end goal of boot9strap powered Custom Firmware. This page will help you find where to start for your device.
The colors of the devices in the image may vary, but note the button placement and features of each device carefully to ensure you select the correct one.
Before starting, you may want to check your SD card for errors using [H2testw (Windows)](h2testw-(windows)), [F3 (Linux)](f3-(linux)), or [F3XSwift (Mac)](f3xswift-(mac))!