expo-eas-ipad-support

A build-time Expo config plugin that fixes iPad apps running in zoomed iPhone compatibility mode.

The Problem

Expo's built-in supportsTablet: true setting in app.json is supposed to set UIDeviceFamily = [1, 2] in the final iOS build. Due to a known Expo bug (#32344), the setting doesn't propagate to the built Info.plist, resulting in UIDeviceFamily = [1] (iPhone only). iPad then runs the app in zoomed iPhone compatibility mode instead of at native resolution.

Installation

npx expo install expo-eas-ipad-support

or

npm install expo-eas-ipad-support

Usage

Add the plugin to the plugins array in your app.json or app.config.js. It should be listed before other plugins:

{
  "expo": {
    "plugins": [
      "expo-eas-ipad-support",
      "expo-router",
      ...
    ]
  }
}

Then rebuild via EAS (native config changes require a new build):

eas build --platform ios

How It Works

The plugin applies two patches to the generated native Xcode project during expo prebuild:

1. Info.plist -- Sets UIDeviceFamily = [1, 2]. This is the key iOS reads at launch to decide whether to run the app natively or in zoomed iPhone compatibility mode.

2. pbxproj -- Sets TARGETED_DEVICE_FAMILY = "1,2" in the Xcode build settings. This is what Xcode uses during compilation to embed the correct device family into the final binary.

Both are necessary because they serve different purposes in the iOS build pipeline.

When It Runs

The plugin is a build-time hook that runs during expo prebuild (which EAS triggers automatically before compiling). It never runs at app runtime.

eas build --platform ios
  |
  +-- expo prebuild (generates native Xcode project from app.json)
  |     |
  |     +-- Config plugins execute here, in order:
  |           1. expo-eas-ipad-support  <-- patches the generated project
  |           2. expo-router
  |           3. other plugins...
  |     |
  |     +-- Native Xcode project is now on disk with correct settings
  |
  +-- xcodebuild (compiles the patched Xcode project into .app)
  |
  +-- .app artifact uploaded to EAS

Local Verification

Verify without a cloud build:

npx expo prebuild --platform ios --clean

# Check Info.plist
plutil -p ios/<AppName>/Info.plist | grep -A3 UIDeviceFamily

# Check pbxproj
grep TARGETED_DEVICE_FAMILY ios/<AppName>.xcodeproj/project.pbxproj

# Clean up generated native project
rm -rf ios/

Characteristics

• Pure JavaScript, ~30 lines
• Only touches the generated throwaway native project (not your source code)
• Zero runtime overhead
• No additional dependencies (uses withInfoPlist and withXcodeProject from expo/config-plugins, already a transitive dependency of every Expo project)

License

Apache 2.0 -- see LICENSE for details.