These terms are thrown around by power users in all the phone forums and this forum is no exception.

It's rarer to find an explanation of what the various terms signify. Do "jailbreak" "unlock", "developer unlock" and "install a customer ROM" all mean the same thing?

If not, what do these terms mean and how do they vary?

And if they do mean the same thing, how do you "unlock" your phone for advanced tweaking?

Since "unlocking" or "jailbreaking" your phone is often part of an answer here, especially when a Windows Phone feature needs tweaking, it would be great if a power user could explain the procedure in terms a novice user can understand.


Phones are often "locked" in some way to stop behaviour that is not intended for general use by one of the phone manufacturer, phone operating system manufacturer or phone network.

Often the actions that are blocked would make it almost impossible to support the device, or would jeopardise the company's business in some manner.

For example, in many regions, handsets are subsidised by the network to which you're connecting, and to encourage you to stay with them, they SIM lock your phone to only work with their network.

Another example is that on Windows Phone OS (and iOS as well), it is not possible to install applications without using the relevant store. To enable developers to properly test their applications prior to public release via the store, this restriction needs to be removed, and essentially is what developer unlocking does (amongst other things). You can probably understand that it would also be difficult to support everyone in the world if they could download and install anything, as well as the security implications of virii. "Jailbreaking" is often meant as a synonym for developer unlocking.

"Unlocking" as a more general term can refer to either the removal of a SIM-lock, or developer unlocking.

Installing a custom ROM is one of the other things you can do with a developer unlocked phone, and it allows installation of an update to the operating system that is not available via the normal channels to the general public.

To developer unlock a device, the process involves setting up a developer account with Microsoft (at a cost of approx 19 USD for individuals and 99 USD for companies, depending on your locale), and using the development tools from Microsoft.

  • What about options for developer unlocking without paying MS $99 per year? I've heard it's possible but don't know details
    – Michael
    Oct 26 '12 at 14:50
  • Microsoft allow members of certain programmes to developer unlock devices for free - I know this has been the case for BizSpark (for startups), and might be available on the DreamSpark programme (for students)
    – Rowland Shaw
    Oct 26 '12 at 16:17
  • 1
    @RowlandShaw re developer unlocking ... is this the same scheme which is currently (win8 launch week) on offer for $8?
    – hawbsl
    Oct 31 '12 at 8:12
  • @RowlandShaw I have developer unlocked 3 phones at no cost via the Preview for Developers app.
    – RareNCool
    Sep 8 '14 at 16:38
  • @Michael Check out this page: dev.windows.com/en-us/develop/devpreview. You can register with app studio for free and this allows you to dev unlock your phone.
    – Mac
    Sep 10 '14 at 2:36

A smartphone is essentially 2 things - A Phone + A Computer.

  1. A phone

    Unlocking is relevant to the phone part of the smartphone.

    In some countries (USA typically), the phone part of the smartphone is locked by the carrier so that it cannot be used with other carriers.

  2. A computer

    Rooting/Jailbreaking is relevant to the computer part of the smartphone.

    The OS of the phone (Android/IOS/Windows) is locked by the Operating System (android/windows/ios) so that you can only access the functionality with the OS and Manufacturer provided interface. You do not have administrator permission on your device (unlike a Windows PC where you can login as an administrator).

    This is done for many reasons
    1. You have to buy through their appstore etc
    2. A lot of users aren't technical enough, hence this is done to protect them from doing something stupid.

    Bypassing these measures to get administrator access to your own device is called rooting or jailbreaking.

  • So how do you become the "administrator", or "root", a WP8 device?
    – NoBugs
    Sep 23 '14 at 6:48
  • @NoBugs - I have not done it but google for Lumia jailbreak and you get a lot of hits.
    – user93353
    Sep 23 '14 at 8:24

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