No crop square photo
A square is 1:1, so the width and the height are the same. This page opens on 1080 x 1080 pixels.
Your photo never leaves this device. To check, open your browser's developer tools, choose Network, and export a photo: no request carries it.
A square frame is 1080 x 1080 pixels with the same width and height, a 1:1 shape. A wide landscape photo fits across the full width and leaves bands above and below; a tall portrait photo fits from top to bottom and leaves bands at the sides. Nothing is removed from either.
Pick Blur if you want the bands to look like part of the picture. The background is a softened copy of the same photo, and the Blur strength slider sets how soft it is; Darken can make it darker. Choose White or Black for a plain border, or Colour to match something else.
Square suits a profile photo that must show a whole face and the space around it, a product shot on a plain ground, or a tile in a collage. If the photo is already square, NoCrop tells you it fits without padding.
Drag the photo inside the preview to move it, use the arrow keys while the preview has focus, or press one of the nine alignment buttons. The Size slider makes the photo smaller than the frame so more fill shows around it.