Talend Data Preparation Free Desktop slowness on Mac: root cause and solution

The MacOS version users may experience an abnormally slow response time when using Talend Data Preparation Free Desktop.


This is due to the App Nap feature which slows down background or inactive applications to save your computer's battery. And because Talend Data Preparation Free Desktop is now a headless application, it can sometimes be considered inactive by App Nap.

The following symptoms show that you may be experiencing this issue:

  • It takes an abnormally long time to open a dataset or a preparation.
  • It takes 10 seconds or more to refresh the list of functions.
  • Nothing happens for a few seconds when you click the lookup icon.

The quick solution to this problem is to click the Talend Data Preparation Free Desktop icon in the dock. The application's performances will go back to normal, but only temporarily.


The permanent fix to this issue is to disable App Nap for Talend Data Preparation Free Desktop. To disable App Nap, proceed as follows:

  1. Open the Terminal.
  2. Enter the following command:

    defaults write org.talend.dataprep NSAppSleepDisabled -bool YES

  3. Restart Talend Data Preparation Free Desktop.

    You have to completely restart the application, not just close and reopen your Web browser.

  • Dataprep