Firefox OS Simulator 4.0

Allows developers to test apps for the operating system

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  • Version:


  • Works under:

    Windows 8 / Windows Vista / Windows 7 / Windows XP

  • Also available for:


  • Program available in:In English
  • Program license:Free
  • Vote:
    6.3 (38)

Mozilla is offering up its own mobile operating system in the form of the Firefox OS Simulator, which is a browser add-on currently in its Alpha stage yet allows you run their in-house OS.

What Firefox OS Simulator Is

Anyone familiar with mobile technology already realizes just how rife the market is with competition. There’s Android, Blackberry, iOS, Windows and others with their own operating systems. Mozilla’s Firefox OS is similar to those other releases, but it’s classic Mozilla through and through. The best part: users get to test out the OS for themselves via the Firefox OS Simulator. So, in other words, you can download the simulator on top of an existing OS to get the feel for Mozilla’s release.

Currently, the Firefox OS is in its Alpha phase. What does this mean? Alpha is the testing phase before Beta, so it could be years before Mozilla puts its OS out for full release. More than likely, the company will brand its OS along with hardware, like a phone or tablet. To date, however, the simulator still offers an OS that’s usable and that works about the same as any other mobile OS you’ll find on the market.

The OS simulates a full operating system’s features by creating an emulation of an OS. Think of it like the old Nintendo emulators you can download online: It’s still Mario Brothers, even if it’s on your computer. The same principles apply here; it’s still an operating system, even though it’s only emulated.

The Features and Function of Firefox OS Simulator

In its early stages, features of the Firefox OS Simulator include a fully functioning app arm of the program that allows users to download and run a variety of applications just like they would on an Android or Apple OS.

Where the emulated OS differs is mostly in aesthetics. Because it’s not a full OS, the text layout can look a bit amateurish at times, while images often appear pixilated and words themselves aren’t always clear. That being said, apps do appear to load rather quickly on the OS, and in true Mozilla fashion, crashing and freezing aren’t big issues at all, even when multiple apps are operating simultaneously.

Being an Alpha-stage program, things are obviously too early in the development of the OS to render a verdict. Though as an emulated operating system goes, the Firefox OS Simulator has earned high praise on a range of different hardware devices.


  • Firefox is a trusted brand across the board
  • The emulated OS is a full-functioning piece of software
  • The OS is stable and more reliable than expected
  • Apps load quickly and operate smoothly


  • The emulator doesn’t pack a ton of features
  • The size of the download is quite large
  • Text and images are rather choppy
  • It’s basically something to try, not something to permanently use

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