fOLDERFUSE

fOLDERFUSE merges the content of a source folder into a destination folder. Files with the same name are replaced, everything else in the destination stays, and the source is left untouched.

In the Finder, copying a folder onto one with the same name asks to replace the whole folder, or to keep both. Modders and anyone used to Windows expect a merge, which is what this app does. You pick a source and a destination, and it shows a summary first: how many files will be replaced and their current size.

Before copying, it checks the free space on the destination. On the same volume, files are cloned, so they use no extra space until they change. A progress bar runs during the merge, stalls are detected, and you can stop cleanly at any time.

The app was written for mod files dropped into a game's Data folder, but it works on any pair of folders. It is written in Swift and weighs about 1 MB. Releases are arm64 builds for Apple silicon, macOS 15 or later, signed with a Developer ID and notarized. A daily check offers new releases without installing anything itself. The interface is in English, French, Spanish and Italian.