Choose a size change or a composition change
Resize Image is a general photo-sizing workflow. Change Image Dimensions is intended for an exact width and height requirement. Image Dimensions reads the source properties without changing the image.
Crop Image removes outer content. Change Image Aspect Ratio helps change the canvas shape using the available crop or padding choices. Use rotation for a sideways image and flipping for a mirrored image.
Keep proportions and important details
Maintain the original ratio when the subject should retain its proportions. If a portrait must fit a square, decide whether to discard outer areas with a crop or retain the subject with padding. Stretching can distort faces and products.
Resizing affects pixel count, not an exact encoded size in KB. Compression is a separate next step when the receiving website also has a file-size limit.