Although Wi-Fi connections are typically quicker than cellular data connections, there are instances where Wi-Fi frequencies are overused. If you are experiencing slower Wi-Fi data speeds at times, the first step is to connect with a different Wi-Fi network or compare data speeds with another device on the same network.
If the issue persists, connect with a 5GHz Wi-Fi network, which is a frequency band that is far less problematic in terms of frequency conflict. To enable or confirm which Wi-Fi frequency band is configured, please refer to the wireless router setup instructions. Typically this is found by signing in to the admin control panel of the router and selecting the 802.11 band from 2.4GHz to 5GHz.