# Preview on iPhone and Android

> Use Studio’s iOS and Android previews on a computer, open the app with Expo Go on your phone, and choose a native test build when needed.

Canonical: https://www.rnblocks.dev/docs/previewing-screens
Updated: 2026-10-01

Use a native preview to see how your app behaves on a phone. Check taps, scrolling, forms and navigation before preparing a release.

## Choose the right preview

Section: https://www.rnblocks.dev/docs/previewing-screens#platform

| Preview | When to use it |
| --- | --- |
| iOS / Android on a computer | Run the app in the selected platform preview inside Studio. |
| My Device on a computer | Use the preview’s QR-code instructions to open the app on your phone. |
| Open with Expo Go on a phone | Switch to Preview, then open the app in Expo Go on that device. |
| Web | Check the browser version. This does not replace native testing. |
| Test build | Test native capabilities and the actual app build you intend to distribute. |

### Figure: Try the app in the iOS preview

The Studio preview panel shows Wandr’s destination discovery screen in an iPhone. On a computer, My Device, Android, iOS and Web sit below the preview, with iOS selected. On mobile, the Preview tab shows the app. The toolbar includes Publish.

1. On a computer, choose iOS below the preview. On a phone, open Preview and use Open with Expo Go.
2. Open a destination, use its actions and check the next screen.
3. Test the Android version too before preparing that release.

Wandr in the iOS preview. Illustrated workspace with recreated native app screens.


## Open the preview on a computer

Section: https://www.rnblocks.dev/docs/previewing-screens#open

1. **Wait for the app preview** — Let the agent finish preparing the app, then open Preview.

2. **Choose iOS or Android** — Select the platform in the preview controls. If the preview shows Launch Snack, select it to start the session.

3. **Try the core task** — Tap through the screens, enter realistic sample text and check loading, empty and error states.


## Try it on your own phone

Section: https://www.rnblocks.dev/docs/previewing-screens#device

On a computer, open **My Device** in the preview and follow the QR-code instructions. On your phone, select Studio’s **Preview** tab and tap **Open with Expo Go**. Use **Download Expo Go** first if it is not installed.

Expo Go runs a fixed set of native capabilities. If your app needs something outside that set, use a development or testing build. A store release also needs its own build; a preview session is not a store submission.

Browser-based OAuth sign-in needs a development build with your app’s own redirect scheme. Native Sign in with Apple has limited iOS Expo Go support; test the final account and sign-in flow in your own build.

- [Choose a native testing path](https://www.rnblocks.dev/docs/publishing/testing)
- [Set up and test social sign-in](https://www.rnblocks.dev/docs/publishing/social-sign-in)
- [Expo: development builds and Expo Go](https://docs.expo.dev/develop/development-builds/introduction/)

## If the preview does not open

Section: https://www.rnblocks.dev/docs/previewing-screens#recover

- Check whether the preview session stopped, and restart it using the visible control.
- Read the actual error. Ask the agent to investigate it in the same conversation; include what you tapped and the platform.
- For connected features, check provider access and credits. A rendered screen does not confirm a real backend request succeeded.
- If one platform works and another fails, report that difference. Avoid regenerating the whole app before identifying the error.


## Continue

- [Expo Go stuck reconnecting](https://www.rnblocks.dev/docs/expo-go-troubleshooting)
- [Test the important paths](https://www.rnblocks.dev/docs/testing-your-app)
- [Troubleshoot a problem](https://www.rnblocks.dev/docs/troubleshooting)
- [Build and test](https://www.rnblocks.dev/docs/publishing/testing)