App Store Connect: File dimensions are invalid

"File dimensions are invalid" means the file you dropped isn't one of the exact sizes that upload box takes. On iPhone, this now catches files that used to upload fine. App Store Connect's iPhone box takes only 1206 × 2622 and 1179 × 2556, plus their landscape versions, so a 1284 × 2778 set gets refused. Check which tab you're on, check the file's size, then export again at a size that box lists.

We hit this ourselves on November 4, 2026, uploading a set made in our own editor. We're Intenseloop, and we make AppScreen (appscreen.pro). This guide comes from what the upload boxes said that day, plus Apple's screenshot specifications and creative assets specifications.

What each upload box takes

Each box lists its supported sizes under the drop area, so read yours first. The iPad and Header rows below come from Apple's spec pages, and the rest from the boxes themselves.

On a Mac, this prints a file's real size:

sips -g pixelWidth -g pixelHeight your-file.png

Why 1284 × 2778 gets refused now

Apple's spec page still lists 1284 × 2778 under iPhone with Face ID (large display), and one line says that set is required if you have no large Dynamic Island set. Its summary says something else: the required iPhone size is Dynamic Island (medium display). The upload box on the version page follows the summary, so we'd go by that.

Screenshots from an earlier version stay on the page under "Using Existing Assets", so you may not notice until you upload new ones. The same page has a View All Sizes in Media Manager link, which we didn't test.

How to fix a 1284 × 2778 set

Export again from your design tool at 1206 × 2622 if you can. That gives you the sharpest result.

If you only have the old files, resize them. The two shapes differ by about 0.5%, so squeezing them slightly is hard to see, and it keeps a panorama's seams lined up where a crop wouldn't. This is what we ran on our own set:

sips -z 2622 1206 old.png --out new.png

Our free screenshot resizer does the same in the browser and flags which box each file already fits.

Check you're on the right tab

App Store Connect now shows a Header and Search Results tab on the version page, next to App Previews and Screenshots. It takes wide banner art only. Drop a phone screenshot there and you get the same "File dimensions are invalid" error. Switch to App Previews and Screenshots.

If there's no Upload button at all

Your version is probably locked. Apple's status reference says that during Waiting for Review you can't upload or edit screenshots or previews.

To change them, remove the submission from review:

1. Open the version in the sidebar and click "remove this version from review" in the message at the top.
2. Or go to App Review, open the submission under Submissions, and click Cancel Submission.

The status changes to Developer Rejected, and resubmitting starts the review over. Apple's wording allows resubmitting your build, so you shouldn't need a new one. If you don't want to wait through review again, leave it running and put the new screenshots in your next version.

Do you need iPhone Duo screenshots yet?

Probably not. Apple says they become required in April 2027 for apps using the iOS 27.1 SDK or later.

Adding them early can work against you. Submitting Duo screenshots adds a badge saying your app is optimized for iPhone Duo. Apple's iPhone Duo guide says an app built with the iOS 26 SDK sits in the center of the open display with empty space around it. Stretching an iPhone set to fit would show a layout your app doesn't have there.

Wait until you build on the iOS 27.1 SDK, then capture from the iPhone Duo simulator in Xcode 27.1. The box takes either display, in one set of up to 10, so a set at 2007 × 2853 is enough to fill it.

Do you need Apple Watch screenshots?

Only if you ship a Watch app. Apple marks them as required for Apple Watch apps. The tab showed up on our version page for an app with no Watch target. Use one size across every language.

Should a Watch screenshot have a frame? Apple's pages don't ban one, and guideline 2.3.3 allows text and image overlays. Real listings tell a clearer story, though. We looked at the first three Watch screenshots of 26 apps in November 2026, 78 images, and none had a drawn watch frame. Nearly all were plain captures of the running app. The sample leans toward fitness apps, but plain captures are the safe default.

What Header and Search Results art is for

These are optional, and Apple says they appear on iOS 27 and iPadOS 27 or later. The upload box says that with no search results asset, your previews and screenshots are used instead.

• Sizes. Header is 21:9 at 3840 × 1646. Search results is 3:2, from 1920 × 1280 up to 3840 × 2560. One 16:9 PNG at 5244 × 2950 can fill both.
• Crop. Keep your focal point in the center, so it survives both shapes.
• Rules. Apple's asset best practices say no prices, discounts, website URLs, or awards you haven't received.
• Review. You can submit them on their own through the Asset Library, with no new app version.

In AppScreen

As of v1.5, AppScreen exports iPhone slides at 1206 × 2622, and your saved works don't change. Free costs $0, with no account and no card, and the first 3 slides of a panorama export clean.

With Pro, $9 paid once, you also get iPhone Duo at 2007 × 2853, Apple Watch at 422 × 514 with no frame by default, and one banner canvas that exports the universal, header and search results files together.

Pro also lets your coding agent do this work. Claude Code, Cursor, Codex, VS Code, ChatGPT and Grok connect over MCP to https://appscreen.pro/mcp, and every change happens on the canvas in your open tab, where you can watch and step in. An agent can switch a work to a new size, upload your screenshots, fix the layout, look at the result and export the files. That's how we made the iPhone Duo, Apple Watch and banner art for one of our own apps the day Apple's box refused our files. Here's how to set it up.

The full list of sizes for every Apple device is in App Store screenshot sizes.