Local File System - Longus/FluidNC GitHub Wiki
The local file system is on the ESP32 device. It is in the flash memory. It is used to store the WebUI files, config files and small gcode files for macros. The space is very limited, so not much can fit on it. It works very similar to the SD card with the commands being prefixed with LocalFS, rather than SD.
Note: The actual term used by the ESP32 community is SPIFFS. You may see or hear reference to that. It is the same thing as LocalFS in this case.
Send $LocalFS/List. The results will look similar to the report below.
[FILE:/index.html.gz|SIZE:122477]
[FILE:/3axis_v4.yaml|SIZE:1762]
[FILE:/favicon.ico|SIZE:1150]
[Local FS Free:44.86 KB Used:124.52 KB Total:169.38 KB]
Send $LocalFS/Show. This is a good way to check the contents of things like config files.
Send $LocalFS/Run=<filename>. This is used to run gcode files.
Send $LocalFS/Format. This will reformat the LocalFS. If you are having trouble loading files when there should be enough space, try reformatting.
Send $LocalFS/Size. The results will look similar to the report below.
SPIFFS Total:169.38 KB Used:124.52 KB
You can access the LocalFS on the FluidNC tab. Click the green icon.

- Upload files with the upload button
- Download files by clicking on the filename in the list
- Delete with the trash can icon.