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Screenshot size checker

Drop your store screenshots to see, for each file, its size, whether it matches a store size Mockuptop exports, whether Google Play will accept its proportions, and whether it has an alpha channel — the stores reject screenshots with transparency.

Files are read by your browser on this page. Nothing is uploaded.

How it works

  1. 01

    Drop files

    PNG or JPG screenshots — as many as you like.

  2. 02

    Read the result

    Exact match, same proportions, Google Play rule and alpha channel, per file.

  3. 03

    Fix

    Rebuild any that fail with the App Store set in the editor — it exports every size without alpha.

What it checks

  • Exact size against the App Store and Google Play sizes Mockuptop exports
  • Same proportions (it would scale cleanly to that size)
  • Google Play: each side 320–3840 px, long side at most twice the short side
  • Alpha channel in PNG files

Questions

Why does the alpha channel matter?

App Store Connect rejects screenshots that contain transparency, and Google Play asks for images without alpha. A PNG saved with an alpha channel can fail even when it looks opaque.

Does it list every size Apple accepts?

No — it checks the sizes Mockuptop exports. Apple accepts more per device class; see the guide for the full list.

Are my files uploaded?

No. The check runs in your browser.

More ways to use Mockuptop