Put it into practice
- Choose the transparent background option.
- Use a format that supports transparency.
- Preview the file on light and dark surfaces.
What this looks like
A device cutout is placed over a website background without a white rectangle.
A detail to keep clear
JPEG replaces transparency with an opaque background in this workflow.
Using MockupX
MockupX exports PNG and JPEG, with WebP and 2× output available to Pro accounts. Export requires sign-in, and free exports carry a watermark. A transparent background remains transparent only in a format that supports it. Inspect the downloaded file, not only the editor preview.
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 ↗