Put it into practice
- Try fit first to inspect the complete screenshot.
- Switch to fill when edge-to-edge coverage matters.
- Check important labels and navigation after the crop changes.
What this looks like
A phone screenshot with required bottom navigation uses fit when fill would cut it off.
A detail to keep clear
Do not assume a filled frame displays every source pixel.
Using MockupX
The editor separates output size from mockup type and layout. After changing a ratio, review every device, crop and text block. These are design decisions rather than automatic guarantees: a layout that works for a wide hero often needs a simpler arrangement on a portrait canvas.
Check the result
Keep the original screenshot, then review the exported file at the size where people will see it. Check the message, the visible interface and the final crop separately. For a handoff, record the destination and the approved file so another person can distinguish the final version from a draft.
References and further reading
Use the official references for format behavior and current destination requirements. The composition advice above is a practical design approach, not a promise of platform approval.
MDN image formats ↗