ITMS-90717: Fix “Invalid large app icon” with Expo

ITMS-90717 is an automated check Apple runs on your build. It says your app's large icon, the 1024 x 1024 pixel one shown on the App Store, contains transparency or an alpha channel. The fix: a square, opaque icon exported without an alpha channel, then a new build.

With Expo, your PNG file is rarely the culprit: prebuild already puts it on a white background. I read that code in SDK 57 and checked the icons of Solys, TradaZen and Nolera. So the error usually comes from a committed ios folder or an Icon Composer file. Here's how to find which one, and fix it.

What does the ITMS-90717 error mean?

The message is titled "ITMS-90717: Invalid large app icon". It says the large icon in your app's asset catalog "can't be transparent or contain an alpha channel". Older messages talked about "Invalid App Store Icon". Same rule.

That large icon is the App Store one. The Xcode documentation on app icons explains it: an app distributed on the App Store must provide its 1024-point icon in its asset catalog.

The alpha channel is the fourth layer of a PNG, next to red, green and blue. It stores the transparency of each pixel. An icon can look solid and still keep that channel: that's the trap that shows up in every forum thread.

Like other ITMS errors, this isn't a rejection by a reviewer. Apple scanned the binary on delivery. Depending on your upload tool, the error shows up as a validation failure, for example with code 409.

Check your icon with sips

On a Mac, sips comes preinstalled. One line is enough:

sips -g hasAlpha assets/icon.png

You want to see hasAlpha: no. On October 15, 2026, I ran this command on the icons declared in the app.json files of Solys, TradaZen and Nolera: all of them return no, at 1024 x 1024.

I also made a test icon: a fully opaque blue square, but saved with an alpha channel. sips returns yes. Not a single pixel is transparent, and the channel is still there. That's why so many developers reply "my icon has no transparency" under this message.

In Preview, the inspector (Tools, Show Inspector) also lists the image properties, including the alpha channel.

Fix it: export the icon without an alpha channel

Three methods, from simplest to most precise.

1. Preview. File, Export, PNG format, then uncheck the Alpha box. The exported file no longer has an alpha channel.

2. sips, nothing to install. sips doesn't remove the alpha channel from a PNG. You have to go through a JPEG, which has none:

sips -s format jpeg -s formatOptions 100 icon.png --out icon.jpg
sips -s format png icon.jpg --out icon-opaque.png
sips -g hasAlpha icon-opaque.png

On my test icon with transparent corners, the corners turned white and the last line returns no. Going through JPEG compresses the image a bit, even at maximum quality: look closely at the result.

3. ImageMagick. If you have it installed, you pick the background color:

magick icon.png -background white -alpha remove -alpha off icon-opaque.png

According to the ImageMagick documentation, -alpha remove puts the image on the background color, and -alpha off turns the channel off.

All three methods fill the transparency with a solid color. If your logo was floating on a transparent background, the cleanest option is to go back to the source file and draw a real background. Expo asks for this in its app icon guide: the icon must fill the whole square, with no rounded corners or transparent pixels. iOS applies the mask itself.

Where Expo gets your icon, and what it does with it

Expo reads ios.icon first, then the root icon field of your config. According to the Expo config reference, ios.icon accepts three forms: a PNG, an object with light, dark and tinted variants, or a .icon folder made with Icon Composer.

The table below comes from the code that generates the iOS icon at prebuild, @expo/prebuild-config 57.0.16 (SDK 57), read on October 15, 2026:

What you declare	What prebuild does	ITMS-90717 risk
icon as PNG	Flattened on white	Low
ios.icon.light	Flattened on white	Low
ios.icon.tinted	Flattened on white	Low
ios.icon.dark	Transparency kept	Intended by Apple
ios.icon as .icon	Copied as is	Real
Committed ios folder	Prebuild not run again	Real

With a PNG, Expo removes the transparency itself and replaces it with white. So a cut-out logo ends up on a white square: no error, but maybe not the look you wanted. The dark variant keeps its transparency, and that's intentional: Apple asks for a transparent background on the dark icon so the system-provided background shows through.

On Nolera, which declares all three variants, sips returns no for the generated light and tinted icons, yes for the dark one. Based on the commit date of those variants, version 1.0.2, which is live, ships them. I haven't checked it in its IPA.

The committed ios folder case

This is the most likely cause with Expo. Expo's page on continuous native generation says it: if your project contains the android and ios folders, EAS Build doesn't run prebuild. Your app.json then no longer touches the icon: the PNG in the ios folder is what gets sent to Apple.

Check it from the project root:

sips -g hasAlpha ios/*/Images.xcassets/AppIcon.appiconset/*.png

If the command returns yes for the 1024 icon, replace that file with your opaque version, under the same name. If you haven't made any manual native changes, you can also delete the ios folder and add it to .gitignore: EAS will regenerate it on every build. On Solys, TradaZen and Nolera, that folder is ignored by git.

The iOS 26 format: Icon Composer

Icon Composer is Apple's tool for iOS 26 Liquid Glass icons. It produces a single multi-layer .icon file. According to Apple's guide on Icon Composer, Xcode also derives the images for older iOS versions from it.

Expo has supported it since SDK 54. You declare the folder as a string, never in the variants object:

{
  "expo": {
    "ios": {
      "icon": "./assets/app.icon"
    }
  }
}

In that case, prebuild copies the folder untouched, and Xcode builds the final icon. So you need Xcode 26 or later, the one in recent EAS images, as I explain in the guide on ITMS-90725.

Since August 2025, threads on Apple's developer forums have reported ITMS-90717 with .icon files. Reported leads: a transparent PNG layer, a layer bigger than the canvas, a group with the Blur effect near the edge. Workarounds mentioned: turn off Blur, keep a solid background, or go back to a PNG. These threads give no official fix from Apple, and the error was still being reported in August 2026.

Apple's guidelines on app icons point the same way: if you import a background layer, it must cover the whole surface and be opaque. My apps still use a PNG, so I haven't tested Icon Composer in production. If a .icon file blocks your upload, switch ios.icon back to a PNG: Expo will flatten it, and your icon will pass this check.

Check the icon in the final build

In the IPA, the 1024 icon isn't a PNG file: Xcode compiles it into Assets.car. Download the IPA from the build page on expo.dev, then run:

unzip -q MyApp.ipa -d ipa
xcrun assetutil --info ipa/Payload/*.app/Assets.car | grep -B3 '"RenditionName" : "App-Icon'

Each icon shows an Opaque field. On October 15, 2026, I compiled the Solys icon and my test icon with transparent corners using actool, Xcode's tool. The first comes out as "Opaque" : true, the second as "Opaque" : false. Apple doesn't document this field: treat it as a hint, not as Apple's check.

One trap to know about: don't test the small PNGs at the root of the app with sips. Xcode writes them with an alpha channel, even when the source is opaque. In my test with the Solys icon, sips returns yes for them.

Other icon errors

Code	What Apple reports	Lead with Expo
ITMS-90717	Transparent 1024 icon	Export without alpha
ITMS-90704	Missing 1024 icon	Missing 1024 entry
ITMS-90022	Missing iPhone icon	Incomplete catalog
ITMS-90023	Missing iPad icon	Incomplete catalog

The last three messages mostly date back to 2017 and 2018, when Xcode 9 changed the icon rules.

With Expo, they've become rare. Prebuild writes a single universal 1024 icon, and Xcode generates the other sizes. With no icon declared, Expo even creates a white square to avoid an upload failure. If one of these errors shows up, look at the committed ios folder: the Contents.json file in AppIcon.appiconset must contain an entry with size 1024x1024, and the PNG it references must exist.

Before your next upload

An icon takes ten minutes to fix, but every error costs you a build. The other automated checks need the same rigor, like ITMS-90683 for permission strings or ITMS-91053 for the privacy manifest. Once the build is accepted, install it with TestFlight to see your icon on your home screen.

Rejections by a reviewer need more perspective: the process is on the app rejected by Apple page, and the most common reasons are in why Apple rejects an app.

To check your submission before sending it, the Review Kit bundles my checklist and Claude Code skills that review your project. If your upload is stuck and you want a human pair of eyes, book an hour with me: we go through your project on a video call, on your screen. And if you're preparing your first release, take the free diagnostic: it puts the steps in order and sends you my Apple anti-rejection checklist.

Frequently asked questions

Why does Apple see an alpha channel when my icon has no transparency?

Because a PNG can keep an alpha channel even when all its pixels are opaque. Many tools add it by default on export. Check with sips -g hasAlpha, then re-export the icon without that channel.

Can you fix ITMS-90717 with an over-the-air update?

No. The icon is compiled into the binary, in Assets.car. An over-the-air update only changes the app's JavaScript and assets. Fix the icon, rebuild, then upload again.

Can the dark icon be transparent?

Yes. Apple asks for a transparent background on the dark variant, and Expo keeps its transparency. My takeaway is that the check targets the main icon, the App Store one: that's the one that must be opaque.

Should you round the corners of an iOS icon?

No. Provide a full square: iOS applies the mask itself. Rounded corners leave transparent pixels in the corners, exactly what this check rejects.

Does Expo support iOS 26 Icon Composer icons?

Yes, since SDK 54: declare the path to the .icon folder in ios.icon, as a string. Prebuild copies it as is and Xcode 26 compiles it. If you hit ITMS-90717 with this format, check for transparent layers and the Blur effect, or temporarily go back to a PNG.