According to our information, there are a few simple ways to determine if an IV checker or an IV machine is illegal. The first is whether it calculates or checks. IV Calculators use game information to make informed guesswork about the IV of your Pokémon. In contrast, checkers usually check the game servers for the exact numbers and this is illegal. Also, calculators never ask for our Pokémon Go credentials, while illegal reviews usually do. If you are not sure, just stick to the IV machines on this list! After all, not all IV machines are in the Play Store.