MustardOS is custom firmware (CFW) for handheld gaming devices

Configurable, themeable, friendly, easy-to-use.

MustardOS gives your handheld a fresh, modern interface that you can shape to suit you. Change the look, the layout and how it behaves, then get on with playing.

MustardOS ships packed with quality of life touches, from the pause menu you land in mid-game to how your library looks and feels. Here is a small taste, refreshed every time you load this page.

Our own Libretro core player, with themed menus, flexible saves, controls, visual tools, multiplayer, and achievements.

Write MustardOS to an SD card with any image flashing tool, then insert the card into your handheld and power it on so MustardOS can set itself up on the first boot.

Always ensure you download from our official download page or supported mirrors!

What began as a small personal hobby project has grown into a thriving community of passionate people who share the same love for games, tinkering, and discovery.

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A quick reference of general frontend hotkeys, plus dedicated Pickles, RetroArch, and LED hotkey tables.