Expo on Desktop

The day two keynote talk at App.js Conf 2026 on 29th May 2026.

Video recording on YouTube.

Transcript

1. Expo is the recommended way to make a React Native app ... for mobile
2. But what about desktop?
3. Expo on Desktop Jamie Birch
4. React Native React Native macOS React Native Windows
5. React Native React Native macOS React Native Windows
6. Should I use React Native Desktop? pitch and anti-pitch
7. Pitch
8. One framework, four platforms
9. Fully native
10. Resource-efficient Electron React Native Electron App size (MB) React Native Electron React Native Electron Memory usage (MB) React Native
11. Trusted Teams Outlook ffi Power Apps Skype Xbox (on Windows) Store (on Xbox) O ce Messenger Start Menu
12. Anti-pitch
13. The community is tiny State of React Native 2025 – "target platforms"
14. The ecosystem is tiny Number of packages on React Native Directory
15. Releases lag behind React Native @latest react-native 0.85.1 react-native-windows 0.82.3 react-native-macos 0.81.7 As of 19th April 2026 major.minor.patch
16. It's hard to set up 1 hour Setting up a React Native macOS app (monorepo)
17. It's complex to deploy
18. Time expenditure Writing business logic Filling in ecosystem gaps
19. Not very encouraging…
20. Expo is the answer
21. • The ecosystem is too small ➡ Expo SDK ➡ Expo Modules API • It's hard to set up ➡ create-expo-app ➡ expo prebuild • It's complex to deploy ➡ Expo Application Services
22. • Small community and lagging releases More users Improve React Native Desktop (via Expo) More contributors
23. What is the state of Expo support for React Native Desktop?
24. CLI support ❌ create-expo-app --template blank-typescript-desktop blank-typescript ❌ expo prebuild --platform macos ios ❌ expo run run:ios run:macos ❌ eas build --platform macos ios ❌ eas submit --platform macos ios ❌ eas update --platform ios macos
25. And yet
27. Expo SDK support Over ⅓ (24 out of 69) of Expo SDK modules for iOS also support macOS
28. Expo Modules API support
29. Expo UI support
30. https://github.com/byCedric/ custom-prebuild-example https://github.com/microsoft/ react-native-test-app fi fi Expo Config Plugins support https://github.com/shirakaba/ ddle-template/tree/con g-plugins/plugins/macos
31. Expo + React Native Desktop Metro Config fi https://github.com/microsoft/ rnx-kit/packages/metro-con g
32. Support for Expo modules written as TurboModules
33. expo run:macos • A line-by-line port of expo run:ios fingerprint.b5b82da… to macOS • Implements Fingerprint, build caching, and everything! My App https://github.com/shirakaba/rnmprebuilds/tree/main/build-cache-provider/src/macos.js https://github.com/shirakaba/rnmprebuilds/blob/main/build-cache-provider/src/cli/ ngerprint.js fi fi https://github.com/shirakaba/expo/tree/@shirakaba/ ngerprint-macos
34. So how can we put all these pieces together?
36. fi • handles all the ddly setup for creating a new app • implements Expo Prebuild • lls in missing parts of the ecosystem fi fi A tool to make React Native Desktop rst-class on Expo.
37. Not vibe-coded
38. Compatibility layer CLI tool
39. Compatibility layer
40. Config plugins Ports of existing plugins Expo has a "default" set of con g plugins. fi fi fi I ported them to macOS. withAssociatedDomains withBitcode withBuildNumber withBundleIdenti er withDeploymentTarget withDeploymentTargetPod leProps withDevelopmentTeam withDisplayName withLocales withPrivacyInfo withProductName withScheme withVersion
41. Config plugins Newly created withExpoAppDelegate withExpoAppCpp
42. Handling side-effects from the entrypoint Expo's app entrypoint triggers a few side-e ects. • Poly lls (e.g. WinterCG) • Initialise Expo Asset and Expo Constants… • … which requires NativeModulesProxy… • … which requires ff fi Expo Modules Core. import { registerRootComponent } from "expo"; import App from "./App"; registerRootComponent(App);
43. Expo Modules Core I implemented a minimumviable Expo Modules Core for Windows. Compiled from the same sources as iOS and Android. common/cpp ├── BridgelessJSCallInvoker.h ├── EventEmitter.cpp ├── EventEmitter.h ├── JSIUtils.cpp ├── JSIUtils.h ├── LazyObject.cpp ├── LazyObject.h ├── NativeModule.cpp ├── NativeModule.h ├── ObjectDeallocator.cpp ├── ObjectDeallocator.h ├── SharedObject.cpp ├── SharedObject.h ├── SharedRef.cpp ├── SharedRef.h ├── TestingSyncJSCallInvoker.h ├── TypedArray.cpp └── TypedArray.h
44. Expo SDK modules
45. (and many other minor things)
46. CLI tool
48. npx expo-desktop create-app
52. 0.81.6 0.81.6 01/11/2025
53. So it's smooth sailing from here?
54. Ease of use We are here Time
55. The ultimate goal is upstream
56. How you can help
57. Star the repo https://github.com/shirakaba/expo-desktop
58. Try to break it npx expo-desktop create-app
60. Thanks for listening! npx expo-desktop create-app Tokyo @shirakaba @birch_js https://birchdocs.tokyo https://github.com/shirakaba/expo-desktop Jamie Birch