Cross-Platform Deployment: Flutter to iOS & Android

Deploying a Flutter app to both platforms simultaneously is one of Flutter's biggest value propositions. But the process has enough platform-specific quirks to trip up even experienced developers. Here's the complete guide.

Prerequisites

Before you start, make sure you have:

flutter doctor

iOS Setup

1. Configure Signing

Open your project in Xcode:

open ios/Runner.xcworkspace

In Xcode:

2. Configure Info.plist

Add required permissions:

<key>NSCameraUsageDescription</key>
<string>This app needs camera access for photos</string>
<key>NSPhotoLibraryUsageDescription</key>
<string>This app needs photo library access</string>

3. Build for iOS

flutter build ios --release

Then archive and upload through Xcode or use:

flutter build ipa --release

Android Setup

1. Configure build.gradle

android {
    defaultConfig {
        applicationId "com.yourname.yourapp"
        minSdkVersion 21
        targetSdkVersion 34
        versionCode 1
        versionName "1.0.0"
    }
}

2. Generate Keystore

keytool -genkey -v -keystore ~/upload-keystore.jks     -keyalg RSA -keysize 2048 -validity 10000     -alias upload

3. Build for Android

flutter build appbundle --release

The AAB file goes to Google Play, APK for direct distribution.

CI/CD with GitHub Actions

Automate both builds:

name: Deploy
on:
  push:
    tags: ['v*']

jobs:
  ios:
    runs-on: macos-latest
    steps:
      - uses: actions/checkout@v4
      - uses: subosito/flutter-action@v2
      - run: flutter build ipa --release
      - uses: apple-actions/upload-testflight-build@v1
        with:
          app-path: build/ios/ipa/*.ipa

  android:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: subosito/flutter-action@v2
      - run: flutter build appbundle --release
      - uses: r0adkll/upload-google-play@v1
        with:
          serviceAccountJsonPlainText: ${{ secrets.PLAY_STORE_KEY }}
          packageName: com.yourname.yourapp
          releaseFiles: build/app/outputs/bundle/release/app-release.aab
          track: production

Post-Deployment

After both stores approve your app:

The whole process takes about 2-3 hours for the first time. After that, tagging a release triggers automatic deployment to both stores.