Skip to main content
Version: 4.2


Windows user?

Try Onion Desktop Tools for easy SD card preparation and Onion installation. ODT makes it easy to format the SD card, download, install, update, and configure Onion in a couple of clicks.

Check your firmware

The firmware is the backend part of the OS, which lives inside your device. Onion on the other hand is a frontend that will stay fresh on your SD card.

Risk of bricking

We can't take responsibility if your device is bricked in the process of upgrading the firmware.

Take a look at the firmware upgrade guide - beware, the guide contains an outdated link to, we provide an alternative download link above.

  1. You can check your current version in SettingsDevice InfoVersion
    or if you already have Onion installed: SettingsAbout deviceFirmware version
  2. Select your device in the tabs below, then check that you have the appropriate firmware version.
'The Boya Incident'

A bad firmware was found on devices bought in late December (version 20221216**** and 20221224****). Please apply the community patch found below. Read more

  1. You need at least firmware version 20220419**** (for Onion v3.10 and above)
    Most devices produced after July 2022 will already have this firmware version.

    • 2021 12 11 0956 ⚠️
    • 2022 01 08 2152 ⚠️
    • 2022 04 19 0828 ✔️
    • 2022 12 16 0314 ⚠️
    • 2022 12 24 0121 ⚠️
    • 2023 01 04 1337 ✔️ (community patch)
    • 2023 06 11 1426 ✔️
Firmware downloads (MM)

Download the installation files

MMP support

You need to install Onion V4.2 for MMP, as earlier versions doesn't support the new hardware.

Download the latest version of Onion:

The Onion installation zip is found under Assets at the bottom of the release notes.
Look for or Onion-v4.x.x-snapshot-[tag].zip.

Install or upgrade

Depending on your situation, choose an option below:


If you experience any issues during the install, try copying over the installation files again and re-run the installation (you can skip copying the BIOS, Icons, and Themes folders).

If you still have issues after trying a reinstall, you may need to reformat your SD card (remember to backup the Roms and Saves folders).