United Airlines offers WiFi on several flights, but only for passengers who have an elite membership in the MileagePlus program or passengers with tickets for the higher classes of the airlines. Passengers can also buy United WiFi, but first, they have to be sure that their flights have WiFi available and then choose the better option according to you. If you need help with WiFi on a plane, you can contact United customer service or read the blog by Airlines Group Travel at the mentioned link.