Put it into practice
- Check whether the browser offers a screen or window picker.
- Choose only the intended surface if capture is available.
- Otherwise take a screenshot with your device and upload the file.
What this looks like
A browser without the needed capture API still accepts a locally saved image through upload.
A detail to keep clear
Permission to capture one window does not mean every browser can capture every surface.
Using MockupX
MockupX accepts pasted, dropped and uploaded images. Screen capture depends on browser support and your permission. The phone-transfer flow uses a temporary upload session. Prepare your source image before decorating it: a frame cannot recover unreadable text or remove sensitive information for you.
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 ↗