Aspect ratio describes shape
Aspect ratio is the relationship between width and height. A 4,000 × 2,500 image has the same 8:5 shape as 1,600 × 1,000, so proportional resizing changes pixel count without stretching the subject.
- Landscape is wider than tall.
- Portrait is taller than wide.
- Square uses equal width and height.
Fit, crop, and padding solve different problems
Fit keeps the complete image inside a target box. Crop fills the box and may remove edges. Padding keeps the whole image while adding background space when the source and canvas shapes differ.
- Use fit when every edge matters.
- Use crop only after checking the removed area.
- Use padding when a fixed canvas is genuinely required.
Avoid changing width and height independently
Forcing a non-square source directly into a square output distorts shapes unless you crop or pad. Choose a proportional width, height, longest-side, shortest-side, or percentage rule instead.