List of free, open source smartphone operating systems

Updated: October 19, 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 a Pixel 3a phone (since it is supported by multiple below operating systems) running Ubuntu Touch or postmarketOS for experimentation before moving to a more expensive daily driver.

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. For the most recent phone support, consider Ubuntu Touch on Fairphone or an Android-based OS on whatever you have.