App Store Connect Screenshot Upload Errors: How to Fix “The Dimensions of One or More Screenshots Are Wrong”

The error that blocks your release at the last minute

You've finished your screenshots, you drag them into App Store Connect, and you get a red message: "The dimensions of one or more screenshots are wrong." Or the upload spins forever. Or the screenshots appear, but App Store Connect still won't let you submit because a required size is "missing."

These problems are different from a review rejection. A rejection happens after Apple's team looks at your content. Upload errors happen before that: App Store Connect's validator simply refuses the file. The good news is that the causes are mechanical and fixable in minutes once you know what to look for.

Error 1: "The dimensions of one or more screenshots are wrong"

This is the most common message. App Store Connect accepts only specific pixel sizes for each display class, in portrait or landscape. Close isn't good enough; being off by one pixel fails.

Commonly used iPhone and iPad sizes (portrait shown; landscape is the same numbers swapped):

Apple updates this list as new devices ship, so confirm against the current "Screenshot specifications" page in App Store Connect Help before you export.

Typical causes and fixes:

• Exported at the wrong scale. Design tools often export at 1× or 2× of the artboard. If your artboard is 440×956 and you export at 2×, you get 880×1912, which isn't accepted. Export at the scale that produces the exact pixel size.
• Mockup tools that add padding. If a device frame or background extends beyond the target canvas, the final image is larger than expected. Make sure the output canvas matches the slot, not just the inner screen.
• Screenshots taken on a device that doesn't match the slot. A raw screenshot from a smaller iPhone won't fit the 6.9" slot. Either capture on a matching simulator or place it inside a correctly sized canvas.
• Mixed orientations. All screenshots in one set are generally expected to share the same orientation. A stray landscape image in a portrait set can trigger the error.
• Hidden resizing by your OS or chat apps. Sending files through messaging apps or some cloud previews can compress or resize them. Upload the original export.

To check quickly on a Mac, select the file and use Get Info, or run:

sips -g pixelWidth -g pixelHeight screenshot.png

Error 2: Alpha channel, transparency, and color profile issues

Apple's screenshot specifications call for images in standard formats without transparency. If your PNG has an alpha channel, the upload may be rejected or behave inconsistently.

Fixes:

• Flatten the image onto a solid background before export.
• Export PNG without alpha, or export as high-quality JPEG, which has no alpha by design.
• Use an RGB color profile (sRGB or Display P3 are safe choices). CMYK files from print workflows are a frequent culprit.

On a Mac, you can strip alpha by converting to JPEG:

sips -s format jpeg screenshot.png --out screenshot.jpg

Or re-export from your design tool with "transparent background" disabled.

Error 3: Unsupported file types and oversized files

App Store Connect accepts common image formats such as PNG and JPEG for screenshots. Files exported as WebP, HEIC, or PDF won't go through even if they look fine in Preview.

Error 4: "Missing required screenshots" even after uploading

Sometimes everything uploads, but you still can't submit. Usually this means App Store Connect wants a screenshot set for a display class you haven't filled.

Things to check:

• The required iPhone size. App Store Connect requires screenshots for at least one of the main iPhone display classes listed in its current help page; other sizes can often be scaled from it. If you uploaded only to a smaller slot, the larger required one may still be empty.
• iPad support. If your app runs on iPad (including when it's a universal app), an iPad screenshot set is required. Either provide iPad screenshots or confirm your target devices.
• Every localization. Screenshots are per localization. If you added a new language, it may fall back to your primary language's screenshots, but double-check that the primary set is complete.
• Other platforms in the same record. If the app also targets Apple Watch, Apple TV, or Mac, those platforms have their own required screenshots.

Error 5: Uploads that hang or silently fail

If the progress indicator never finishes:

1. Try another browser. Safari and Chrome both work, but extensions such as ad blockers or privacy tools can interfere.
2. Upload fewer files at once. Dragging ten large PNGs into several slots at the same time can stall. Do one set at a time.
3. Check your network. Corporate proxies and VPNs sometimes break large uploads.
4. Reload and verify. After a refresh, confirm which screenshots actually saved before re-uploading, to avoid duplicates.
5. Use the API for bulk work. Teams shipping many localizations often automate uploads with the App Store Connect API or tools built on it, which also gives clearer error messages.

Error 6: Screenshot order and count problems

App Store Connect allows a limited number of screenshots per set (up to 10 at the time of writing). If you try to add more, the extra files will be rejected. Also note:

• The order you arrange in App Store Connect is the order users see. Re-check it after bulk uploads, because files can land out of sequence.
• Deleting and re-adding a screenshot may move it to the end of the set.

A pre-upload checklist

Run through this before you open App Store Connect:

• Every file matches an accepted pixel size for its slot exactly
• All screenshots in a set share the same orientation
• No alpha channel; flattened background
• RGB color profile (sRGB or Display P3), not CMYK
• PNG or JPEG, not WebP/HEIC/PDF
• File names sorted in display order (e.g., 01-hook.png, 02-feature.png)
• Required iPhone set filled; iPad set filled if the app supports iPad
• Each localization reviewed
• No more than the maximum screenshots per set

Prevent the problem at the source

The most reliable fix is to export from a template that's already locked to the exact sizes App Store Connect accepts. Whether you build templates in Figma, Sketch, or a browser tool such as appshotmaker.com, keep one canvas per display slot, export without transparency, and name files in order. Then the upload becomes a drag-and-drop step instead of a debugging session.

Summary

Most App Store Connect screenshot upload errors come down to four things: pixel dimensions that don't exactly match a slot, transparency or CMYK color, unsupported file formats, and missing required display sizes. Check those before uploading, and save your review time for the things that actually need human judgment.