Why does my iPhone have slow Wi-Fi?
All iPhones are slow on my home Wi-Fi. Pc, Mac, Xbox, and my wife's old droid run great but my old iPhone 4 and mine and my wife's iPhone 5's are slow? Changing the dns did nothing
Added (1). The iPhones use standard 802.11a/b/g/n Wi-Fi (802.11n 2.4GHz and 5GHz) so there's no reason why they should be noticeably slower than anything on the network.
Are you sure they are switching to the Wi-Fi connection and not still using the cellular/mobile network?
I know it's switching to Wi-Fi. The LTE is really fast.