Managing Save Files and Autosaves
How Factorio save files work, where they are stored, how autosaves rotate, and how to load a specific save.
Overview
Factorio saves are .zip files stored in factorio/saves/. Understanding how saves work is critical for recovery, server transitions, and version upgrades.
Save File Location
All saves live in:
factorio/saves/
This includes both manual saves and autosaves. On WISP/Pterodactyl, you can browse and download save files via the Files tab in the panel.
Loading a Specific Save
Pass the save path to --start-server:
./factorio/bin/x64/factorio --start-server factorio/saves/myworld.zip
On WISP/Pterodactyl, the startup variable for the save name is typically SAVE_NAME. Set it in the Startup tab. The egg will pass it to --start-server automatically.
Autosave Behavior
Autosaves are controlled by two fields in server-settings.json:
{
"autosave_interval": 10,
"autosave_slots": 5
}
autosave_interval— How often (in minutes) the server saves automatically.autosave_slots— How many autosave files to keep. When the slot limit is reached, the oldest autosave is deleted.
Autosave files are named:
autosave_1_20260427T143022Z.zip
autosave_2_20260427T153022Z.zip
...
With 5 slots and 10-minute intervals, you have a 50-minute rolling backup window. For detailed tuning advice, see Tuning Autosave Settings and Recovering from Backups.
Save Compatibility
- Forward-compatible: A save created on an older Factorio version will load on a newer version. The server will migrate it automatically.
- NOT backward-compatible: A save created on a newer Factorio version cannot be loaded on an older version. Never downgrade a server without testing on a save copy first.
When updating the server, keep a backup copy of your save before the first run on the new version. See Updating the Factorio Server and Managing Compatibility.
Transferring a Save Between Servers
- Stop the source server.
- Download the
.zipfromfactorio/saves/via the panel Files tab. - Upload it to
factorio/saves/on the destination server. - Set
SAVE_NAME(or--start-server) to the new file name. - Start the destination server.
If the destination has mods, the save will fail to load unless the mod set matches exactly. See Installing and Managing Mods.
Manually Creating a Save
To create a fresh save without starting the server:
./factorio/bin/x64/factorio --create factorio/saves/newsave.zip
To create with custom generation settings:
./factorio/bin/x64/factorio --create factorio/saves/newsave.zip \
--map-gen-settings factorio/config/map-gen-settings.json \
--map-settings factorio/config/map-settings.json