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FAQStart Building

Live preview

Preview your Expo app in the browser with device frames and real-time updates.

The preview panel renders your app inside a simulated phone frame using browser-metro — an in-browser Expo bundler. No local Node.js install is required.

Device frames

Switch between device profiles such as:

  • iPhone (multiple sizes)
  • Google Pixel
  • Samsung Galaxy

Toggle landscape orientation when testing wide layouts. Preview supports an optional ambient background preference.

Real-time updates

When the AI edits code or you save in the editor, the preview rebundles and refreshes automatically. Complex changes may take a few seconds to compile.

Preview logs

Open the preview logs panel to see Metro bundler output, errors, and warnings. Use this to debug red screens or import failures without leaving OpenV2.

QR and device preview

For testing on a physical phone:

  1. Open the QR menu in the header
  2. Choose Expo Go — syncs your project to a cloud Metro server and shows a scannable QR code
  3. Or open the live web app URL if you've published

See Preview on device.

Visual editor integration

In Design mode, click elements directly in the preview iframe to select and style them. See Visual editor.

Limitations

  • Browser preview approximates native behavior — always test critical flows on a real device
  • Some native modules may not run in Expo Go; use Native builds for store-ready testing