In Preview you can test responsive layouts: pick a device preset or type a custom width×height, and rotate to swap width and height.
Where: Preview toolbar → device/size controls — Enter Preview mode
Key ideas
- Presets & custom: Choose a device preset or enter a custom width and height.
- Rotate: Swap W/H to test portrait vs landscape.
Steps
- Enter Preview mode.
- Pick a device preset or set a custom size.
- Rotate to flip orientation.