In order to achieve this, you have to set the following widget attribute: data-crop to “1:1, free”. This will give your user two presets. The user will be able to select the square region or any other region he’d like.
For example, user uploaded the following image:
and selected the following region using a manual crop:
You want to get square 600x600 picture for your site. You can append following
-/preview/600x600/-/crop/600x600/center/ to URL of the selected image and you’ll get the following result:
In case the user selected the whole image without actually cropping it, you’ll also get a square image with paddings: