Deactivating and deleting are two different operations here, and only one of them removes data.
Deactivating
Deactivating stops the plugin registering its modules and extensions. Every setting stays where it is, and so does everything you built: module settings are stored in the content of the pages that use them, not in a table of ours. Reactivate and the same pages render again with the same choices.
Before you delete
- Export anything you want to keep. A Divi layout export covers the pages; a WordPress export covers the posts.
- If you use Custom Login Page, note which pages are assigned to which authentication state. Those pages survive deletion, but the assignment does not.
- If you use Popup Maker in Pro, open Squad Popups → Settings and decide what If this plugin is deleted should say. It is set to keep your popups, and it only acts on deletion.
- Delete Pro first if you have both, then the free plugin. Each has its own cleanup and Pro’s expects the free plugin to still be loadable.
What deleting the free plugin removes
- Every option whose name begins
divi_squad_ordivi-squad_, autoloaded ones included. Your active module and extension lists are one of those options. - Every transient under those two prefixes, together with its timeout row.
- The site’s
divi_squad_custom_fieldstable, dropped.
On a network that sweep runs per site, across every site rather than the first hundred, and it includes archived and spam sites so nothing is left behind on one you had forgotten.
What deleting Pro removes
Only its own keys, the ones beginning divi_squad_pro_, per site and across the network’s own options. It drops no tables and it does not touch the free plugin’s settings, so deleting Pro and keeping the free build leaves your module list exactly as it was.
What deletion does not touch
Your posts, pages and Divi layouts. A page built with a Squad module keeps that module in its content. With the plugin gone nothing renders it, so the section disappears from the page until the plugin is back. Reinstalling restores the output but not your module list: that list was an option, options were deleted, so it starts again from the shipped defaults.
The records that survive
Two extensions create content rather than settings, and content is not the plugin’s to remove:
- Custom Login Page creates four pages, Login, Register, Lost Password and Reset Password. They stay in Pages after deletion, so delete them yourself if you do not want them.
- Popup Maker in Pro stores each popup as a post. It deletes them, and their statistics, only if you asked it to on its settings screen. The default is to keep them, because moving hosts and reinstalling to clear a fault both go through deleting a plugin, and neither means you wanted the popups gone.
Scheduled Content is in between: uninstalling clears every schedule, its stored dates and the scheduled events behind them, and leaves the posts exactly where they are, including any that an expiry already moved to draft.