Fx0 / LGL25 / Madai

The LG Fx0 / LG-L25 / Madai is a high-end consumer Firefox OS smart phone, and marks the very first Firefox OS phone release in Japan. It was released by KDDI in December 2014.

On release, the Fx0 was available to buy through standard Japanese retail channels. Being a SIM-locked device, it could only be used in Japan.

More recently (late 2015/early 2016), GSM unlocked phones became available, sold by various online shops.

Most of the information on this page comes from the good people at /r/fx0. Special thanks to Cutol for doing all the hard work porting stuff to this phone.

ProcessorQualcomm Snapdragon S4 MSM8926 1.2GHz quad-core
Battery2370 mAh
Rear Camera8 Megapixels
Front Camera2.1 Megapixels
Internal Memory16 GB
External MemorymicroSDXC (64GB max.)
Stock OSFirefox OS 2.0
Size70x139x10.5 mm
WeightApprox. 148g


This site attempts to catalog of all the information and software that exists for this phone. There is a list of tutorials for installing new operating systems and other Fx0 specific modifications. You can find a local mirror of all the refrenced files on the downloads page. If you are looking to buy an Fx0 you can visit the vendors page for a list of possible sellers.

Operating Systems

Currently working operating systems for the Fx0 include:

The only available recovery partiton at the moment is TWRP 302

Firefox 2.0 Japanese variant screenshots