Here is a way to “export” a Wunderlist list as a JSON Array:

  • Open your favorite and up to date browser
  • Login into Wunderlist
  • Select one of your list
  • Open your browser Developer Console
  • Type: Array.from(document.getElementsByClassName("taskItem-titleWrapper-title")).map(item => item.innerHTML) and press Enter
  • Right click on the printed object then click on “Copy Object”

That’s it!

As it’s based on the CSS Class name of a list item it might change in the future, if that does not work just check what is the new CSS class.

Tested with Firefox 67.0.1, on June 13th 2019.