It does not have pre-heat settting - if that's a thing.
If I turn it on as I am doing something like an egg wash of a pie or topping a lasagne to finish them off then by the time I put the food in - a couple of mins at most - it cooking hot. I just take the tray out, plonk whatever I am cooking on it and shove it back in.
At 20l its capacity is similar to that of a large air fryer if that helps.
It took a while getting used to because I tended to leave food in for the same length of time as a "normal" oven and some things got burnt due to the fan and the higher temps. And I have to beware of which heating setting(s) I am using - top. bottom or both. Fortunately it has a glass door and a lamp so I can do things by eye if I want to.