Other iPhone 5S to 10.3.3?

[Apple_Glen_UK]

Quick question; I am looking at buying a new iPhone 5S but I'm wary about going onto iOS 11.3 as I have read that for the iPhone 5S it can slow it down.

I don't want any other phone - I'm happy with a 5S.

If I get a new 5S, would it be possible to get it onto 10.3.3?

 

[Banglazed]

The 5S will have some hardware limitation on iOS 11.3 but would suggest to get the SE (similar to 5S size but better processor) instead. Depends where you buy the device, most are probably updated to iOS 11 but it may still possible to buy one on iOS 10 either on eBay, Amazon or pawn shops. If you get a 5, you can guaranteed the highest supported iOS 10.3.3.