Designing UI for Mobile in 2023

I always engineer to the default CanvasScaler of 800 x 600, set to match height. See below.

This approach lets all my projects have compatible parts. Any other custom resolution approach is not helpful unless somehow you have hard-coded numbers, and nobody that I know designs UI that way. And even if they did, a little math and you can scale it to 800 x 600… so why not stick with that to start?

Here are some notes on UI Anchoring, Scaling, CanvasScaler, etc:

Usually you need to choose a suitable ScaleMode and MatchMode in the Canvas Scaler and stick with it 100%. Generally if you change those settings you will often need to redo your UI entirely.

I also use this CanvasScalerOrientationDriver utility to make sharing UI for Landscape / Portrait easier. Read what it does carefully.