List of free, open source smartphone operating systems

Updated: September 24, 2025

I hope to experiment with these, post some experiences, and move away from closed-source big vendor smartphone operating systems. The most interesting devices might be a Fairphone running Ubuntu Touch or a recent Google Pixel with GrapheneOS. Also considering an old cheap Pixel phone running Ubuntu Touch or postmarketOS for experimentation before moving to a more expensive daily driver.

• postmarketOS — based on Alpine Linux
• Ubuntu Touch — based on Ubuntu
• Mobian — based on Debian
• PureOS — from Purism

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• LineageOS — based on Android
• GrapheneOS — based on Android

Devices

This is an incomplete list of devices commonly supported by above mobile operating systems. There are many more but these seem to be more recent.

• Fairphone 4
• Fairphone 5
• Google Pixel 3a
• OnePlus 6
• OnePlus 6T