How long does it take to update my iPhone?

Update iphone

Update your iPhone, iPad, or iPod touch - Apple Support

Over the air ("OTA") using Wi-Fi should take about 30 minutes depending on internet speed.

Check all of these carefully:-

·       you are on a good Wi-Fi,

·       Plenty of spare storage – 6GB at least.

·       on charge with more than 20%, OR 

·       off charge with more than 50%

·       low power mode turned off. 

·       Check Settings, General to make sure you have no Beta profile installed.

·       no VPN installed (Check Settings, General, VPN & Device Management)