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Troubleshooting Mobile App Testing Issues with the Expo Go App

Learn why CodeHS mobile app programs may not run on Expo Go and explore simple workarounds to keep testing your code

Talia Smith avatar
Written by Talia Smith
Updated this week

If students are unable to run a CodeHS React Native/Expo program on a mobile device, it may be due to a version mismatch between Expo Go (the mobile app used to run Expo projects on iOS or Android devices) and Snack (the online platform used to run and preview Expo projects in a browser and generate QR codes for testing on mobile devices).

Expo Go version error messages may say something like: "This Snack is incompatible with this version of Expo Go."

Screenshot of the error message regarding incompatible versions on the Expo Go app

Workarounds for Mobile App Testing

When the latest Expo Go version is not yet supported by CodeHS, you can:

  1. Run the code in the CodeHS Code Editor's mobile device emulator: Click Run in the Output window to test your program in the built-in emulator.

    Screenshot of the program in the CodeHS editor pointing to the run button

  2. Test your code on Expo Snack: Copy the code from the CodeHS Code Editor and paste it into https://snack.expo.dev/ to generate a QR code compatible with the latest Expo Go version.

    Screenshot of the Snack site (<a href="https://snack.expo.dev/" target="_blank" rel="nofollow noopener noreferrer">https://snack.expo.dev/</a>) to paste your code into and get a QR code from the 'My Device' tab on the right hand side

    (Note: The Snack website may experience a short delay with supporting the latest version of Expo Go when a new version is released, so this workaround may not immediately work.)

Why Expo Go Version Issues Occur

The Expo Go app only supports the latest Expo release, and occasionally that version becomes newer than the one used on CodeHS. This happens because Expo maintains two libraries: the Expo SDK, which the Expo Go app relies on, and the Snack SDK, which CodeHS uses to run apps in the browser and send them to mobile devices. Updates to the Snack SDK sometimes lag behind new Expo releases. When this happens, the CodeHS browser emulator will still work, but scanning the QR code with the Expo Go mobile app may result in an error.

This version mismatch is temporary and resolves once the supporting libraries get updated.

Still have questions? Contact our team at support@codehs.com to learn more!

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