How to Upload a Factorio Save to a Server (Single Player to MP)

To upload a Factorio save to a server, copy the save zip from your Factorio saves folder into the server's saves folder, then start the server with that save: --start-server yoursave.zip on a self hosted server, or by replacing the save the hosted server already loads. Any single player or multiplayer save works, as long as the server runs the same or a newer Factorio version and has the same mods. Here is the full process.

Step 1: Find your save file

Factorio keeps each save as one .zip file:

Paste the Windows path into the File Explorer address bar to jump straight there. Pick the file with your save's name. Files called _autosave1.zip and so on are autosaves, which are fine to use too if they are newer.

Do not unzip it. The server loads the zip as it is.

Step 2: Check version and mods

Version: the server must run the same Factorio version as the save, or newer. A save made on 2.0.77 loads on 2.0.77 or later, but not on an older server. After uploading, everyone joining needs the server's exact version.

Mods: look at the mods you used in that game (Settings, Mods in the main menu, or mods/mod-list.json in your Factorio folder). Every mod that changes the map needs to be on the server. If a mod is missing, the server either refuses to load the save or removes that mod's content, which can wipe entities from your factory.

Space Age: if the save uses Space Age, the server needs space-age, quality and elevated-rails enabled in mod-list.json, and every player needs to own the expansion.

Factorio can also sync mods the other way round: when players join a modded server, Sync mods with server downloads the exact versions from the mod portal. That only helps players, the server itself must have the mods installed.

Step 3: Upload the save

• Self hosted: copy the zip into the server's saves folder, for example factorio/saves/.
• Hosted server: stop the server, take a backup, and upload the zip into the saves folder with the file manager. For big late game saves, an SFTP app like FileZilla or WinSCP is more reliable.

Large megabase saves can be hundreds of MB, so give the upload time to finish before starting the server.

Step 4: Load it

Self hosted

Point the server at your save:

./bin/x64/factorio --start-server ./saves/my-factory.zip --server-settings ./data/server-settings.json

Or use --start-server-load-latest without a file name, which loads the most recently saved file in the saves folder. If you just uploaded an old save, the server's own autosaves may be newer, so naming the file is safer.

Hosted server

A hosted Factorio server loads one save by name. Look in the saves folder to see the file it is currently running. Rename your upload to that exact name, replacing the old file (after your backup), and start the server. Check the console: it prints which save it loads and whether any mods are missing.

Step 5: Add the mods to the server

Upload the same mod zip files into the server's mods folder, and make sure mods/mod-list.json has them enabled. The simplest way is to copy the mod zips straight from your own mods folder, since those are the exact versions your save used. Restart the server.

Step 6: Join and check

Connect, look around your base, and check trains, bots and power are running. Then make yourself admin with /promote YourName in the server console. See Factorio server commands for the rest.

Moving a save off a server

The reverse works the same way: stop the server, download the save zip from its saves folder, and put it in your own saves folder. It then shows up in Load game in single player.

Common problems

• Error saying the map version is higher than the game version: the save came from a newer Factorio than the server. Update the server.
• Mods missing on load: install the same mods on the server, in the versions listed in the error.
• Server loads an old map instead of yours: it loaded a different file, often a newer autosave. Name your file exactly and start it by name.
• Players get "Version mismatch detected!": after an upgrade, players need the server's version. See Factorio version mismatch fix.
• Save not showing in single player after download: make sure the file ends in .zip and sits directly in saves, not in a subfolder.

The easy way

On a Factorio server from GamezServers you click Backup, upload your save in the file manager or over SFTP, and press Start. Your factory then stays online with its own address, so friends can keep building without you hosting. Setup takes about a minute, see how to host a Factorio server.

FAQ

Can I play my single player Factorio save in multiplayer?

Yes. Any save zip loads on a server with the same or newer version and the same mods.

Where are Factorio saves stored?

%appdata%\Factorio\saves on Windows, ~/.factorio/saves on Linux and ~/Library/Application Support/factorio/saves on macOS.

Do I need to unzip the save?

No. Upload the zip as it is.

Will achievements still work after moving to a server?

Moving a save does not affect achievements. Using Lua commands or cheats does.