Enter exact width and height when a destination specifies pixels. Keep ratio lock on for simple scaling. For a different canvas shape, choose Fit to show everything or Fill to cover the frame.
Pixels and aspect ratio
Pixels describe resolution; ratio describes shape. Both 1080 × 1350 and 2160 × 2700 are 4:5, but the second contains four times as many pixels.
Pixels, percentage or long edge
Use pixels for an exact canvas, percentage for a proportional copy and long edge to normalize portrait and landscape images consistently.
Fit versus Fill
Fit shows the complete source and adds background space when shapes differ. Fill covers the target and center-crops overflow. Both use one uniform scale, so neither stretches the source.
Practical social presets
Platforms change and may recompress uploads. The tool shows its official references and review date instead of treating presets as permanent rules.
Upscaling
A larger canvas cannot recover missing detail. Use the smallest dimensions the destination accepts and keep an untouched original.