How Can We Help?


After designing a device or extension on mBlock 5 Extension Builder, you can debug it in one of the following ways:

  • Client
  • On the web
  • Mobile app


  1. Download the extension as an .mext file on mBlock 5 Extension Builder.
  2. Drag the .mext file to the mBlock 5 client on a PC.
  3. Restart the mBlock 5 client.

You can start to test the extension.


  • Each timer after you drag an .mext file to mBlock 5, you can restore the extension to the latest online version by clicking the download button in the upper right corner of the extension icon.

For example, after dragging the mBuild extension to mBlock 5, you can click   to restore the latest online version.


On the web

1. Publish the extension you have developed on mBlock 5 Extension Builder.

2. Enter the test environment and sign in with the account (usually an account for testing) you have used to publish the extension.

3. Refresh the browser.

You can see the extension and start to test it.

Note: It is suggested that you use an account different from the one you use to develop the extension for testing to prevent unexpected changes.

Mobile app

Currently, tests on mobile apps are not available to users.