How do you transfer videos from your computer to iPhone
To get videos from your computer to your phone, you'll need a Lightning-to-USB cable. Plug one end into your iPhone, and the other into your computer's USB port. Open iTunes on your computer and go to File > Devices > Transfer Purchases From "iPhone" > [Choose Files]. Select the video you want to transfer and click Add. Then connect your phone to your computer with its regular charging cable. Once the transfer is complete, you will be able to view the video in the Photos app on iOS or by clicking Videos in iTunes on your computer.