WiFi Slow, 4G Fast topic

I recently started using my N5 phone and when I first got it everything on the phone was fine and pretty fast. However, recently, my WiFI has been going very slow. When I'm on my data, the phone moves pretty fast online, but when I turn on the WiFI, especially internet pages take so long to load sometimes. Any suggestions on a fix or what the problem is? Thanks.

Also, I recently wiped the phone completely and started from scratch and the problem is still there. The problem is not the router as other devices work fine on it. Also, I'm on stock 5.0.1. Thanks.