I have used them as hand luggage before. 👍🏻

I now only travel with this bag as hand luggage and have never had a problem even when full to the brim! Even then it looks smaller than most suitcases

From practical experience I can say that I often take size S with me as hand luggage, and I've never had any problems with Easyjet. Just put it on as a backpack and they have never complained or asked me to hand in the bag.

XS goes as hand luggage
S is actually too big for as hand luggage, but if you still fill it full, it should be iO. Tighten straps.

If the dimensions are correct, it is too long, too wide and too high - i.e. NOT hand luggage.