Some users notice a folder appear in their asset library without notice, or conscious action on their part, labelled “base64data”.
This folder effectively contains images that would normally be encoded within a database by Foundry VTT, such as thumbnails or images pasted into a journal entry. In effect, it’s a location for random images that needs to exist for typical Foundry VTT functionality, and doesn’t belong in the user’s game data folder. Some modules will also attempt to store images in the same way.
In the interest of sparing our user’s game data storage limits and improving game performance, we push these images into a directory within the user’s asset library. Fortunately, the images will continue to work seamlessly within Foundry VTT, and there is very little difference apart from a folder being created within the user’s asset library.
We do not recommend deleting items within this folder, unless they are unusually large in size. We strongly recommend making a backup if forced to delete something.