Previewing
Every prototype on RNBlocks can be previewed in two ways: live on a real phone, or instantly in the browser. No account needed for either.
On your phone
There are two options for previewing on a phone. The right one depends on whether you want a quick look or the full native experience.
Option A, Browser preview (quickest)
On mobile, tap the preview link or QR code to open a web-based preview directly in your phone's browser. No app to install, it opens instantly.
This is the fastest way to get a first look, but some native features, haptics, certain animations, and platform-specific behaviors, won't work in a browser environment.
Option B, Expo Go (full native feel)
Expo Go is a free app that runs the prototype natively on your device, real animations, real haptics, real platform behavior. This is the closest experience to using the actual app.
To open in Expo Go from your phone:
- 1Install Expo Go and open it.
- 2On an RNBlocks screen or prototype page, tap "Open in Expo Go".
- 3Your phone's browser opens, tap "Open with Expo".
- 4The prototype runs natively, fully interactive, full animations.
On desktop
On desktop, every prototype has an embedded live preview in the browser, a phone-shaped frame that lets you see the app without switching devices.
Using the in-browser preview
- 1Open any prototype or screen on RNBlocks.
- 2The preview panel loads on the right side of the page. Click Launch preview if it isn't running yet.
- 3Interact with the prototype directly in the browser, tap through screens, fill in forms, scroll lists.
- 4Use the device selector to switch between iOS and Android styling.
Scanning the QR code (open on phone from desktop)
- 1Open Expo Go on your phone.
- 2Tap the scan icon in the top-right of the Expo Go home screen.
- 3Point your camera at the QR code shown in the desktop preview panel.
- 4The prototype opens immediately on your phone, no extra steps.
Browser vs Expo Go
| Browser preview | Expo Go (native) | |
|---|---|---|
| Native feel | Approximate | ✓ Exact |
| Animations | Most work | ✓ All work |
| Haptics | ✗ | ✓ |
| Native packages | Limited support | ✓ Full support |
| Load time | ~3 s | 3–10 s |
| Install required | No | Expo Go app |
| Account required | No | No |
For the most accurate feel, especially animations, haptics, and gestures, use Expo Go on a real device. The browser preview is good for a quick visual check.
Frequently asked questions
Does preview work on Android?
Yes. Expo Go is available on both iOS and Android. Both platforms get the same live native preview.
Do I need an account to preview?
No. Previewing is completely free with no account required. You only need to sign in to use AI generation or copy code.
The QR code isn't working, what should I try?
Confirm your phone and computer are on the same Wi-Fi network. If it still fails, use the "Open in Expo Go" button and tap "Open with Expo" on your phone's browser instead.
The web preview is spinning and won't load
Try refreshing the page. If it still fails, hard-refresh (Cmd+Shift+R on Mac, Ctrl+Shift+R on Windows) or switch to Chrome, which tends to be most reliable.