OnionOS

Spec sheet

Product

Onion is an operating system overhaul for the Miyoo Mini and Miyoo Mini+.Read 3 Oct 2026 · onionui.github.io

Support

The project directs users to GitHub Discussions, Discord, Reddit, and Facebook for community support.Read 3 Oct 2026 · onionui.github.io

Activity tracking

The Activity Tracker records game playtimes, displays total playtime in the top bar, and lets users share playtime screenshots.Read 2 Oct 2026 · onionui.github.io

Connected features

On Miyoo Mini Plus, Onion supports OTA updates, date and time synchronization, game-cover scraping, and network services including SMB, HTTP, SSH, FTP, Telnet, hotspot, and VNC.Read 3 Oct 2026 · onionui.github.io

Customization

Tweaks lets users adjust system settings, enable network services, and configure button shortcuts; themes can change backgrounds, categories, icons, music, and fonts.Read 3 Oct 2026 · onionui.github.io

Device requirements

The installation guide requires at least firmware 20220419 on Miyoo Mini and 20230505 on Miyoo Mini+; Onion runs from the SD card as a frontend to the device firmware.Read 3 Oct 2026 · onionui.github.io

Emulation

Onion includes RetroArch with dedicated drivers, custom overlays and filters, plus standalone PCSX and ScummVM emulators.Read 3 Oct 2026 · onionui.github.io

Game collection tools

Its Search app finds games by keyword, and its Game List Options menu can select cores, fetch cover images, launch Netplay, and filter lists.Read 2 Oct 2026 · onionui.github.io

Game library

Search finds games by keyword, and Activity Tracker records playtime and displays total playtime in the top bar.Read 3 Oct 2026 · onionui.github.io

Game switching

GameSwitcher lets users browse recently played games and resume them with screenshots showing where they left off.Read 2 Oct 2026 · onionui.github.io

GameSwitcher

GameSwitcher lets users browse recently played games and resume them from a screenshot of where they left off.Read 3 Oct 2026 · onionui.github.io

Installation

Onion is installed and kept on an SD card; the maker says Windows users can use Onion Desktop Tools to prepare the card and install or update Onion.Read 2 Oct 2026 · onionui.github.io

Installation support

Windows users can use Onion Desktop Tools to format an SD card and download, install, update, and configure Onion.Read 3 Oct 2026 · onionui.github.io

Known limitation

The FAQ says a MainUI issue can prevent Wi-Fi networks with special characters from connecting, and reports no fix because MainUI is closed source.Read 3 Oct 2026 · onionui.github.io

Multiplayer

Netplay supports online or local network sessions; Easy Netplay on two Miyoo Mini Plus devices needs no prior Wi-Fi setup, and Pokémon trading is available for GB/GBC.Read 3 Oct 2026 · onionui.github.io

Network features

On Miyoo Mini Plus, Onion offers Netplay, over-the-air updates, time synchronization, cover scraping, and network services including SMB, HTTP, SSH, and FTP.Read 2 Oct 2026 · onionui.github.io

Notable limitation

The built-in game image scraper is available on Miyoo Mini Plus only, according to the FAQ.Read 2 Oct 2026 · onionui.github.io

Package Manager

The Package Manager app installs and uninstalls emulators and apps.Read 3 Oct 2026 · onionui.github.io

Ports

The Ports Collection page describes 61 game ports; some require users to provide licensed game files.Read 3 Oct 2026 · onionui.github.io

Where Specifiction places it

• Emulation Frontends#24 of 256.8