iPhone X and XS discalmer
The dimensions of the iPhone X and XS are strictly identical: 14.4 cm high, 7.1 cm wide and 7.7 mm thick. In theory, a case for the iPhone X can fit the iPhone XS. However, there is a barely noticeable difference between the two models that has to do with the antennas for improved 4G speeds.
The iPhone XS has seven holes on the right side of the Lightning connector and only four on the left. The iPhone X has six holes on each side. To avoid covering these antennas, it is recommended to choose a case specifically designed for the iPhone XS.