iPhone is slow on Wi-Fi network

If your iPhone feels slow, it could be due to a slow or unstable internet connection. Many apps and features rely on the internet to function properly, and if the connection is weak, they may lag, freeze, or take longer to load.

To determine if the issue is internet-related, try using features that do not require an internet connection. These include making phone calls, sending SMS messages (not iMessages), using the Clock app, browsing offline photos in the Photos app, or accessing downloaded content. If these functions work normally while internet-dependent apps remain slow, the issue is likely with your internet connection rather than the device itself.

If you connect to Wifi, doesn't necessarily mean you are connected to the internet. --> Internet not available WiFi and Cellular … - Apple Community