Cannot load into Pokemon go when using wifi
Solution 1:
If it works on Mobile data but not Wi-Fi, the problem is in your Wi-Fi.
Several things you may want to check if Wi-Fi isn't working for you:
Check that your Wi-Fi actually has internet (i.e. check that you can view websites and such). It is very likely that you may be connected to Wi-Fi but have no internet connection, such as if your router has an internet connectivity problem.
Extreme case: Check that your internet provider does not block any websites/databases from where information is necessary, such as real-time data for Pokemon and Pokestops.
Extreme case: Check that if you have an app to monitor apps and what types of data connectivity, including mobile data and Wi-Fi, that they can use, Wi-Fi is not blocked for Pokemon Go. In other words, check that Pokemon Go is allowed to use Wi-Fi on your device.
It is possible that their servers may have been knocked down temporarily and that no one can connect to it. Not very likely, but it could happen.