Root: Rooting means you have root access to your device—that is, it can run the sudo command, and has enhanced privileges allowing it to run apps like Wireless Tether or SetCPU. You can root either by installing the Superuser application or by flashing a custom ROM that includes root access.P
ROM: A ROM is a modified version of Android. It may contain extra features, a different look, speed enhancements, or even a version of Android that hasn’t been released for your phone yet. We won’t discuss ROMs in depth here, but if you want to use one once you’re rooted, you can read more about doing that here.P
Kernel: A kernel is the component of your operating system that manages communications between your software and hardware. There are a lot of custom kernels out there for most phones, many of which can speed up your phone and increase your battery life, among other things. Be careful with kernels, though, as a bad one can cause serious problems with your phone and possibly even brick it.P
Radio: Radios are part of your phone’s firmware. Your radio controls your cellular data, GPS, Wi-Fi, and other things like that. You can sometimes find custom radios for your phone that you can flash yourself, but beware as sometimes these can cause problems.P
Flash: Flashing essentially means installing something on your device, whether it be a ROM, a kernel, or a recovery (see below) that comes in the form of a ZIP file. Sometimes the rooting process requires flashing a ZIP file, sometimes it doesn’t.P
Brick: To brick your phone is to break it during flashing or other acts. There is always a small risk with flashing, and if your phone becomes unable to function—that is, it basically becomes a brick—you’ve bricked your phone. The risk is very small, however, and more often than not people say “brick” when they really mean “it turns on but doesn’t boot properly,” which is a very fixable problem. See the FAQ below for more information.P
Bootloader: Your bootloader is the lowest level of software on your phone, running all the code that’s necessary to start your operating system. Most bootloaders come locked, meaning you can’t flash custom recoveries or ROMs. Unlocking your bootloader doesn’t root your phone directly, but it does allow you to root and/or flash custom ROMs if you so desire.P
Recovery: Your recovery is the software on your phone that lets you make backups, flash ROMs, and perform other system-level tasks. The default recovery on your phone can’t do much, but you can flash a custom recovery—like ClockworkMod or TWRP—after you’ve unlocked your bootloader that will give you much more control over your device. This is often an integral part of the rooting process.
Nandroid: From most third-party recovery modules, you can make backups of your phone called nandroid backups. It’s essentially a system image of your phone: Everything exactly how it is right now. That way, if you flash something that breaks your phone, you can just flash back to your most recent nandroid backup to return everything to normal. This is different from using an app like Titanium Backup that just backs up apps and/or settings—nandroid backups backup the entire system as one image. Titanium backups are best when switching between ROMs or phones.
ADB: ADB stands for Android Debug Bridge, and it’s a command line tool for your computer that can communicate with an Android device you’ve connected to it. It’s part of the Android Software Developers Kit (SDK). Many of the root tools you’ll find use ADB, whether you’re typing the commands yourself or not. Unless the instructions call for installing the SDK and running ADB commands, you won’t need to mess with it—you’ll just need to know that it’s what most of the tools use to root your phone.
S-OFF: HTC phones use a feature called Signature Verification in HBOOT, their bootloader. By default, your phone has S-ON, which means it blocks you from flashing radio images—the code that manages your data, Wi-Fi, and GPS connections. Switching your phone to S-OFF lets you flash new radios. Rooting doesn’t require S-OFF, but many rooting tools will give you S-OFF in addition to root access, which is nice.P
RUU, SBF, and OPS: ROM Upgrade Utilities (for HTC phones), System Boot Files (for Motorola phones), and OPS and PIT files (for Samsung phones) are files direct from the manufacturer that change the software on your phone. RUU and SBF files are how the manufacturers deliver your over-the-air upgrades, and modders often post leaked RUU and SBF files for flashing when the updates haven’t been released yet. They’re also handy when downgrading your phone, if a rooting method isn’t available for the newest software version yet. You can flash RUUs right from your HTC phone, but Motorola users will need a Windows program called RSD Lite to flash SBF files, and Samsung users will need a tool called Odin to flash OPS and PIT files (note there is a specific version of Odin for each device).
People have a lot of questions about rooting, and we hear them all the time. Here are some of the most frequently asked, laid out so you don’t have to ask someone else.
What’s the difference between rooting, unlocking, and flashing a ROM? This can be confusing, since the three practices are often performed at the same time. We’ve detailed some of this above, but briefly: Unlocking your bootloader is usually the first step in the process and allows you to flash a custom recovery. From there, you can then give yourself root access or flash a ROM. Root access isn’t required to flash a ROM, but almost all custom ROMs will come with root access built-in.
Note that when we say “unlock” in this guide, we mean unlocking your bootloader—not unlocking your phone to use a different carrier, which is a completely different thing and doesn’t always require hacking (since you can often purchase carrier-unlocked phones directly from Google or elsewhere).
Can I unroot my phone? Yes. If you decide you don’t like being rooted, you can often find instructions on unrooting your phone as well. Usually it involves flashing an RUU, SBF, or something similar to return the phone to truly stock settings.
Is rooting illegal? No. Technically, it once was, but exceptions to the DCMA have made it legal for most phones (but not necessarily tablets). Either way, it’s hard to imagine anyone actually enforcing this rule (much like ripping DVDs for your own personal use).
Will rooting void my warranty? Yes. Unlocking your bootloader will void the warranty on your phone, even if your manufacturer provides a way for you to do it. That said, if you need warranty service for a hardware issue, you can sometimes unroot your phone and take it in for service with no one the wiser. However, some phones have a digital “switch” that flips when you unlock your phone that is very difficult or impossible to revert, so do your research before unlocking if you want to preserve your warranty.
Could rooting brick my phone? It’s possible, but pretty unlikely. As long as you follow instructions well, you probably won’t brick anything (but we’re not responsible yadda yadda yadda). Flashing custom kernels and radios is a little riskier than just rooting or flashing ROMs, but again, if you follow directions you should be okay. Keep in mind that bricking means your phone means it won’t turn on or function at all—if you’re stuck in a boot loop or boot straight to recovery, your phone is not bricked, and it can be fixed.
re any phones unrootable? This is a tough question. In the past, many manufacturers have tried to make “unrootable” phones with harsher protections (like the Droid X), but they’re usually still rootable in some way, shape, or form. The more likely scenario is that, if you get a new phone or a phone that had a recent update, that a root exploit isn’t available yet. In that case, you may have to wait a few months before you’re able to root it. This is one of the reasons we recommend buying a Nexus.
Will I still get over-the-air (OTA) updates? Will downloading them break my root? If you root your phone without flashing a custom ROM, then you will likely still get OTA updates from your carrier, and they will break your root. We highly recommend against downloading these updates, since you may not be able to re-root your phone for awhile after updating. Alternatively, you can use an app like OTA Rootkeeper that will help you keep your root access (though it doesn’t work with every version of Android).
If you flash a custom ROM, you will not get OTA updates from your carrier. You may, howaever, get notifications for updates to your specific ROM. Those are safe to download.
Will rooting speed up my phone? Not on its own—all rooting does is give you root access. However, it does open up the possibility for other tweaks that can speed up an old phone.
Can you tell me how to root my [insert phone model here]? NO. Please don’t email us asking this. We only own a few phones and thus probably don’t know how to root yours. Check out the section below to find out where to find information on how to root your phone.