But I see they put the ROM build URL on Google drive.

Are unofficial roms safe. The use of emularots is completely legal. It is safe to download and run Android emulators to your PC. And this site will allow you to play backups.

It is never 100 safe to install custom rom. It also occasionally hosts coding competitions. Of course this is the main reason that it is completely safe to download ROMs from this platform without the issues of malware.

Steer clear of any UNOFFICIAL builds from individuals you cannot research. It offers fun for various consoles and also games that have been legalized by the authors for free usage. However it can be considered illegal if you have never owned the game.

It is safe to use. Official ROM- Provided by mobile manufacturers tested and stable as well as safe. How can I be sure that build is coming from.

Yes it is legal to download ROMs if you own a copy of the game that you are trying to download. However you need to be aware of where you are downloading the emulator. Im using unofficial carbon rom for my secondary phone which is a samsung Grandis it safe to use unofficial custom rom coz i cant find an official one for it.

If you already own the copy of the game that you are trying to download the ROM for then yes it can be considered legal. To be honest with you the answer is neither a yes nor a no. Privacy depends upon you yourself.