How to uninstall Polylang?

There are two things to understand when uninstalling or removing Polylang or Polylang Pro.

• If you deactivate and delete the plugin from WordPress, you only remove the plugin and its files. Your settings, languages and information linking translations together will still exist in the database.
• If you need to remove ALL Polylang data, including languages, settings, etc., you need to be able to modify the site’s wp-config.php file before deactivating and deleting the plugin.

To fully remove all Polylang data from your WordPress site, open your site’s wp-config.php file. Add define( 'PLL_REMOVE_ALL_DATA', true ); on its own line above the /* That's all, stop editing! Happy publishing. */ line.
Then when you deactivate and delete Polylang or Polylang Pro it will remove all of its data from your WordPress site database.