This question always strikes newbies’ minds when they think of flashing a custom ROM for the first time. Is flashing or making a custom ROM legal? After all, it isn’t the phone’s manufacturer that has made or certified the custom ROM, so could it land us up in any legal trouble? Well, let us explain.
First of all, just in case you’ve forgotten, or you didn’t know, Android is open source. It’s in the name itself: AOSP, which stands for Android Open Source Project. You can skip to the next paragraph from here if you don’t want to read about licensing details of Android (but we think you should read it, it’ll just take one extra minute, and some extra knowledge never hurts). For the more legal heads among you, the majority of codes of the Android Open Source Project are licensed under the Apache 2.0 license and some codes & modules under the GPL v2 license. Apache 2.0 and GPL v2, both allow anyone to view, edit, modify, run and release a variation of the software, as long as they don’t falsely represent the software to be their own original property. Read more about AOSP’s licensing here.
This alone is the answer to the question. Basically, Android can be modified and distributed freely, and that’s only until the modified software does contain only the open source codes and modules licensed under Apache 2.0 and/or GPL v2. That is why we added the word ‘almost’ right at the beginning of this post.
Someone who has been flashing ROMs for more than a couple of years will remember that earlier, custom ROMs came with Google apps (GApps) included inside the ROM package. Google later asked ROM developers to not include GApps inside ROM packs. The reason? Because these GApps are proprietary, and can’t be distributed or included inside AOSP without purchasing a license from Google. This seems a bit confusing at first, but it isn’t. AOSP is free to modify and distribute, but GApps and some other software that Google adds inside their then Nexus now Pixel stock OS aren’t.
So what have we concluded up until now is that making or installing custom ROMs without any license-bound codes or apps or modules is a hundred percent legal. Example- Lineage OS. On the opposite side, making (or rather porting) and/or flashing ROMs that have codes that require a legal purchase is illegal. Example – ROMs based on something like HTC’s Sense UI, or Samsung’s TouchWiz, because those are proprietary.
But, here’s one very good thing about the Android community. Except for some very rare occasions, OEMs will not discourage people from making or porting ROMs, or flashing and using them. Rooters, modders and flashmaniacs are the most enthusiastic Android users out there, and when this community speaks, both the OEMs and Google listen. They’re (we’re) a very important part of the Android community, and their (our) choices and interests affect the Android ecosphere massively. In very rare occasions, OEMs might ask the developers to take the ROM down, but there hasn’t been any case yet when a ROM user has been found in some legal trouble for using a ported custom ROM. OEMs can file lawsuits against the developers, so most of them avoid including proprietary codes and apps anyways. So, no, the police won’t come and arrest you for flashing a ROM that even includes some proprietary codes and apps. In both cases, if you’re the user and not a developer, you’re fine with flashing with any custom ROM of your choice. If you’re a dev, just avoid proprietary forks, unless you’ve got a very strong reason not to 😉
Hope it helped. Happy flashing!