Debug builds

How to enable debug mode and collect logs for troubleshooting

If you encounter issues while running an applet with CheerpJ Applet Runner, enabling Debug Mode can provide detailed logs that help our support team identify the problem.

Enabling Debug Mode

To enable the debug build of CheerpJ:

  1. Click the CheerpJ Applet Runner icon in your browser’s toolbar.
  2. In the popup page, toggle the “Enable debugging mode” switch to On.
  3. The extension will now use the debug version of the runtime, which includes extensive logging.

Collecting Debug Information

To help us troubleshoot, we typically need two files: the Console log and a Network HAR file.

Step 1: Open Browser DevTools

You must open the browser’s developer tools before the applet starts loading, or reload the page once they are open.

  1. Press F12 (Windows/Linux) or Cmd + Opt + I (Mac) to open the DevTools.
  2. Alternatively, right-click anywhere on the page and select Inspect.

Step 2: Save the Browser Console Output

Follow these instructions to save the browser console output.

Step 3: Extract a HAR File

Follow these instructions to extract a HAR file.


Once you have collected these files, please attach them to your support request or bug report.