How to crop pictures within Photos app on an iPhone 13?

Tia-Angel wrote:… Will it work if I only need one side cropped off?

It crops to the size of the screen, so it's a quick crop for showing people pictures on the phone.

If you want something different than that, you can go to Edit Mode.

In Edit you choose Crop, and then you can move the corners as you wish. You can also pick common sizes with the icon indicated by the blue arrow.

In addition to the Edit Mode method that Phil0124 suggested, you can just zoom in (by pinching) to the size you want,

and then select "Crop" to keep it that way.

What iOS version is your iPhone running?

What trouble are you having exactly?

For iOS 18, open the Photos App, tap on a photo to open it, top on the adjustment icon at the bottom, and then on Crop.

Great!