**First check if `ios/` and `android/` directories exist in the project.** If neither directory exists, the project uses Continuous Native Generation (CNG) and native projects are regenerated at build time — skip this section and "Clear caches for bare workflow" entirely.
If upgrading requires native changes:
```bash
npx expo prebuild --clean
```
This regenerates the `ios` and `android` directories. Ensure the project is not a bare workflow app before running this command.
## Clear caches for bare workflow
These steps only apply when `ios/` and/or `android/` directories exist in the project:
- Clear the cocoapods cache for iOS: `cd ios && pod install --repo-update`
- Clear derived data for Xcode: `npx expo run:ios --no-build-cache`
- Clear the Gradle cache for Android: `cd android && ./gradlew clean`
## Housekeeping
- Review release notes for the target SDK version at https://expo.dev/changelog
- Update versioned docs links in agent instruction files (`AGENTS.md`). The default template links to `https://docs.expo.dev/versions/v<version>/`. Search for `docs.expo.dev/versions/` and bump each link to the new SDK version.
- If using Expo SDK 54 or later, ensure react-native-worklets is installed — this is required for react-native-reanimated to work.
- Enable React Compiler in SDK 54+ by adding `"experiments": { "reactCompiler": true }` to app.json — it's stable and recommended
- Delete sdkVersion from `app.json` to let Expo manage it automatically
- Remove implicit packages from `package.json`: `@babel/core`, `babel-preset-expo`, `expo-constants`.
- If the babel.config.js only contains 'babel-preset-expo', delete the file
- If the metro.config.js only contains expo defaults, delete the file
| expo-linear-gradient | experimental_backgroundImage + CSS gradients in View |
When migrating deprecated packages, update all code usage before removing the old package. For expo-av, consult the migration references to convert Audio.Sound to useAudioPlayer, Audio.Recording to useAudioRecorder, and Video components to VideoView with useVideoPlayer.
Exclusions are often workarounds that may no longer be needed after upgrading. Review each one.
## Removing patches
Check if there are any outdated patches in the `patches/` directory. Remove them if they are no longer needed.
## Postcss
- `autoprefixer` isn't needed in SDK +53. Remove it from dependencies and check `postcss.config.js` or `postcss.config.mjs` to remove it from the plugins list.
- Use `postcss.config.mjs` in SDK +53.
## Metro
Remove redundant metro config options:
- resolver.unstable_enablePackageExports is enabled by default in SDK +53.
- `experimentalImportSupport` is enabled by default in SDK +54.
- `EXPO_USE_FAST_RESOLVER=1` is removed in SDK +54.
- cjs and mjs extensions are supported by default in SDK +50.
- Expo webpack is deprecated, migrate to [Expo Router and Metro web](https://docs.expo.dev/router/migrate/from-expo-webpack/).
## Hermes engine v1
Since SDK 55, users can opt-in to use Hermes engine v1 for improved runtime performance. This requires setting `useHermesV1: true` in the `expo-build-properties` config plugin, and may require a specific version of the `hermes-compiler` npm package. Hermes v1 will become a default in some future SDK release.
## New Architecture
The new architecture is enabled by default, the app.json field `"newArchEnabled": true` is no longer needed as it's the default. Expo Go only supports the new architecture as of SDK +53.
## Submitting Feedback
If you encounter errors, misleading or outdated information in this skill, report it so Expo can improve:
