If you are wondering how perfect your Pokémon is, this is your thread. These are some of the most used IV calculators from the Reddit community.
Before we start, use the apps we list below under your own responsability
The overlay app for android takes a screenshot to calculate the perfection of your Pokémon. Also, it doesn’t access the API so it is pretty safe.
The same as GoIV but for iOS.
Alternative to GoIV for android.
One of the first web-tools to check the IVs of your Pokémons.
Another web-tool to check out the IVs of your Pokémons.
Web-tool that doesn’t take a screenshot as an input, but it shows many useful information (and doesn’t use the CP arc, so it’s precise).
Similar to Goptimiz, a source to compare in case you doubt. It includes other tools like a chart with the moves of the game and rankings of attackers and defenders.
Another web-tool to know the IV’s of your Pokémon. It also has other interesting tool like Pidgey spam calculator or a catch change calculator.