Getting screenshots past the tools that block them
The screenshot step of a release fails at the upload gate more often than at review, and the errors are terse enough that the obvious fix is usually the wrong one. Each page here starts from the message the tool actually prints and ends with a command you can run.
App Store Connect upload errors
“The dimensions of one or more screenshots are wrong”
App Store Connect accepts a fixed list of pixel sizes per display slot, not a range or an aspect ratio. Read the file's real pixel dimensions, find the exact pair on Apple's list for the slot you are uploading to, and re-export at that size. Scaling an existing file to fit almost always lands one pixel off.
4 steps | verified 2026-09-01
“Images can't include alpha channels or transparencies”
The alpha channel is a property of the file, not of anything you can see, so an image with no visible transparency still carries it. Re-encode the file as JPEG, or strip the channel from the PNG with ImageMagick. Renaming the extension does not change the bytes and produces a different error.
4 steps | verified 2026-09-01
“The images are not in the right format”
A file extension is a label, not a format. Renaming a PNG to .jpg leaves PNG bytes behind a JPEG name, and App Store Connect reads the bytes. Re-encode the file with a tool that actually transcodes it. App Store Connect accepts .jpeg, .jpg and .png.
4 steps | verified 2026-09-01
Recipes
App Store screenshots for an Expo app
EAS builds and submits your binary, and EAS Metadata pushes your store listing, but Expo documents screenshot upload as unsupported in EAS Metadata. Screenshots stay a separate step you handle in App Store Connect or a third-party tool, and an Expo project needs two sets because it ships to both stores.
Expo / EAS | 5 steps | verified 2026-09-01
Generate screenshots in GitHub Actions
Call the AppScreenshotStudio REST API from a workflow step: create a project, send one chat message describing the app, then render. The render endpoint returns image URLs you can download and publish as build artifacts. Authentication is a bearer token you store as a repository secret.
GitHub Actions | 6 steps | verified 2026-09-01
Related reference
These pages carry the procedure. For what is true and why, the answers and reference surfaces carry the rules and the tables.