Firefox OS is an operating system for smartphones and tablets that’s designed to run web apps. It’s developed by the makers of the Firefox web browser, and included on a handful of phones sold in parts of Europe, South America, and Asia.

Up until recently most Firefox OS phones have been entry-level devices, but Japanese wireless carrier KDDI has just introduced a model which has the specs of a modern, mid-range smartphone… and a bit more style than most other mid-range phones.

The KDDI Fx0 smartphone with Firefox OS launches on Christmas Day in Japan.


The phone features a 4.7 inch IPS HD display, a 1.2 GHz Qualcomm Snapdragon 400 quad-core processor, 1.5GB of RAM, and 16GB of storage as well as a microSDXC card. It has an 8MP rear camera, a 2.1MP front-facing camera, and a 2,370mAh battery.

Mozilla calls it the first “high-spec Firefox OS smartphone,” but it really seems to have the kind of specs we’d see from a mid-range Android phone. Still, it’s one of the most powerful Firefox-powered phones to date. It’s also the first to support 4G LTE.

The Fx0 is also the first Firefox OS device with a transparent case that lets you see the battery, memory card, and some of the circuitry that’s under the hood. Mozilla’s mobile operating system is based on open source software, and part of the idea here is to present a phone that’s literally as transparent as Firefox.

While most Firefox OS phones released so far have been low-cost devices with entry-level specs, there’s nothing about the operating system that would keep it from working with higher-end hardware. Mozilla and its partners have just been going after the largely untapped market of first-time smartphone buyers in developing markets. If the Fx0 is a success it could pave the way for more Firefox OS devices with mid-range or high-end hardware.


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10 replies on “Japan’s Fx0 is the most powerful Firefox OS phone yet”

  1. I want and need Firefox OS in my phone provided Mozilla doesn’t renege on their commitment to privacy. (Remember Google’s “Don’t be Evil”? – yeah right…). I won’t let my SIM cards anywhere near my Android devices because of Google’s spying, and lax app permissions that are beyond most user’s control. Firefox still has some time – as long as they get it right. But they don’t have forever, and at this late stage I’m getting concerned.

  2. You’ve lost me at “Firefox OS phone”

    At this point Firefox OS feels like a “too little, too late” last ditch effort of Mozilla to try and stay relevant in times where more and more usage of the web shifts from the Desktop (which they lost to Chrome) to Mobile (where they only made half hearted efforts with sluggish Firefox Ports for established Platforms).

    The current Desktop Firefox UI apes Googles Chrome because they feel otherwise people won’t even concider using them anymore, and 6-7 years after iOS and Android apeared on the Mobile Scene they come out with a “me too” OS which, with its focus on Web Apps is pretty much what Chrome OS is to Desktop OSes, so their whole OS essentially isn’t even a “real” mobile OS with its own App Ecosystem, but really just a minimalist Linux that runs the Firefox Browser. Web Apps however will run all the same on the established platforms in browsers, where as Firefox OS neither runs iOS nor Android Apps. With quadcore 720p Android phones under 90 EUROs, i really don’t see the point of “entry level” OSes.

    1. I heartily disagree on many fronts. Google’s offerings on the desktop and mobile are polished, modern, and fast. And they spy on you like the NSA only wishes it could. Most of us either don’t know or don’t care, but I can easily imagine a niche market of people who actually do care… As a side note, I don’t think the Android port of FF is half-hearted, it’s not bad at all (and there’s not much they could do on iOS).

      1. The price of “free” online is userdata, at least if you only use legal offerings. I’m not saying google is the be all, end all – but Firefox OS has a bad value proposition. It essentially is a glorified webbrowser, and its apps are just websites, it – by design – does nothing that couldn’t be acomplished on ANY platform with a webbrowser, yet tries to establish itself as an alternative platform by offering less than all its competitors. At this point Ubuntu Touch with full convergence, or even sailfish OS look way more viable as a 4th option than Firefox OS.

    2. Google is helping the US government do all kinds of controlling, spying and murderous things around the globe. This fact and the fact they are trying to control the market in every aspect – operating system, email, VOIP, document processing etcetera, etcetera, is good enough reason not to support them. I really hate to give a link to newsweek but Julian Assange among others has shed light on this –

      1. In the full picture Google is not helping the US government. Just like anyone else Julian Assange has expressed his opinion on the relationship, but considering his arguments he is unable to provide proof for his thesis.

    3. FirefoxOS is awesome on many fronts, most notably it is a ecosystem free product with enough polish to function as a great simple all round device. This isnt a product competing against Android’s feature set, not by a long shot, and it doesn’t pretend to try. I have no idea why this perspective comes up wrt to FirefoxOS but it makes no sense.

      Personally i love the bloat free experience of firefox os, and have bought FireFoxOS devices for people who dont need a full smartphone but do want email, browser, text product.

      Not everyone is looking to buy an ecosystem product that’s a ‘computer iin your hand’ there’s plenty of demand out there for straight up communications devices.

      1. My Problem with Firefox OS isn’t with what it is or isn’t capable of, it is with the fact that you can get similar or even better specced Android Offerings for the same Money or even less, and don’t see the point in a platform that can do significantly less, that doesn’t also cost significantly less.

  3. So this is the Pixel Chromebook of smartphones?
    Not sure the clear case is a good idea. Scratches will make the case look terrible.
    Any idea how many apps are available for these devices?

    1. The surface is already intentionally bumpy (not sure what word to use). You can click on the images to see zoomed-in photos here:
      With that surface I’m unsure that scratches will make a significant difference to the appearance.

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