If you’re looking to trade in your iPhone X for the iPhone XS but can’t figure out what to do with your iPhone X cases, well, you don’t need to worry about it. The iPhone X and iPhone XS are of the same dimensions. All your iPhone X cases will fit perfectly fine on the iPhone XS as well.
This is, of course, applicable in the opposite direction as well. If you like the new cases Apple introduced for the iPhone XS, you can buy and use them on your iPhone X too.
The iPhone XS Max and iPhone XR, however, are bigger than the iPhone X. They won’t fit in your iPhone X cases if you were wondering.