Skip to main content
Testing on physical devices is crucial for mobile development. Blox provides a seamless bridge from your browser to your phone.

​
Using the QR Code

Every Blox project has a unique development QR code. Scanning this in the Blox Preview app connects your device to the local dev server.

​
Prerequisites

  1. Download the Blox Preview app from the App Store.
  2. Ensure your phone and computer are on the same Wi-Fi network (or use a Tunnel).

​
Live Reloading

Blox uses a specialized Hot Module Replacement (HMR) engine.
  • UI Updates: When you change a color or font, your phone refreshes instantly.
  • Logic Updates: Changing API calls or state logic will trigger a fast refresh, preserving your app’s state.

​
Debugging

You can view logs and errors directly in the browser console of the Blox Editor.
Large assets (unoptimized images) may slow down initial load times on the preview app. We recommend using SVG where possible.

​
Simulator Access

If you don’t have a physical device handy, you can use the In-Browser Simulator. This uses an emulated environment to show you exactly how your app will look on various screen sizes.

Open Simulator

Enter the Blox Builder to launch the browser simulator.