Satisfactory: Save Editor
Rename a session so the new name actually sticks, and see what is in a save before a dedicated server has to load it. Runs in your browser; the file is never uploaded.
?sessionName= token in the map options, and two properties
(mSaveSessionName, mReplicatedSessionName) deep in the compressed save
state. Rename fewer than all four and the game quietly restores the old name on the next
autosave. This editor rewrites all four, fixes the size bookkeeping the change cascades into,
and re-validates the result before you download it.
Pick a .sav
Local game: %LOCALAPPDATA%\FactoryGame\Saved\SaveGames, then your account id
folder. From a dedicated server: download the save first (on Supercraft that is the
SaveGames folder in the panel file manager, or FTP). A .bak is a rotated
copy - rename it to .sav to use it.
Read and edited locally. Nothing is uploaded.
Rename the session
This save predates Update 8, and the old format is not worth the risk of editing blind. Load it once in the current game so it is rewritten in the modern format, then bring the new .sav back here.
You get a new .sav named after the session; the original
file on disk is untouched. Upload the new file to your server (or drop it in your local
SaveGames folder) and load it from the save list.
Want this on a real server? Supercraft hosts Satisfactory →
Renaming a session on a dedicated server
The server manager has no rename button, so the loop is:
- Stop or pause play, and download the current save from the server. On a Supercraft Satisfactory server that is the SaveGames folder in the file manager; other hosts expose it over FTP.
- Drop the .sav on this page, type the new name, download the renamed file.
- Upload it back through the in-game server manager (or the same file manager), then load the new session from the server's save list.
- Delete the old session once you have loaded in and seen your factory.
Same flow works for the classic move of bringing a solo or co-op world onto a server: name the session something recognisable here, check the build and modded flags below, then upload.
What the inspection tells you
- Build version - the game build that wrote the file. A server on an older build will not load a newer save; update the server first.
- Modded flag and mod metadata - if mods were loaded when the save was written, the server needs the same mods at compatible versions, or the load fails or quietly drops modded content.
- Session name - what every save list shows. A blank one uploads fine and is then nearly impossible to identify; that is the other thing the rename fixes.
Server up but nobody can connect? That is a port problem, not a save problem: test the port.
FAQ
Why not just rename the file?
The file name is cosmetic. Save lists group and label by the session name stored inside the file, and on modern saves the header even records the original file name separately. Renaming the file changes none of that.
Is the checksum a problem?
Saves from 1.0 onward carry a consistency hash in the header. The game does not refuse edited saves over it, and renamed saves load normally - the same mechanism every save editor relies on.
What about a 500 MB endgame save?
Fine, and faster than any upload-based tool, because there is no upload. The heavy part runs on your machine with the browser's built-in compression engine. Very large saves briefly need memory in the same ballpark as the save's uncompressed size, so a desktop browser is the right place for a monster factory.
Can it edit inventories, unlock research, or move things on the map?
No. Those are map-editor jobs and SCIM does them well. This page stays deliberately narrow: inspection and renames, done conservatively - if anything about the file looks unexpected, it refuses instead of guessing, and your original is never modified.
How do I rename a Satisfactory session or world?
Renaming the .sav file is not enough: the session name is stored inside the save, in four places. The header carries a sessionName field and usually a ?sessionName= token in its map options, and the compressed save state carries mSaveSessionName and mReplicatedSessionName properties. All four have to change together or the game reverts the name on the next autosave. This page rewrites all four in your browser and hands you back a renamed .sav.
Can I change the session name of a save on a dedicated server?
Not from the server manager - it has no rename. The working path is: download the save from the server, rename it with a tool like this one, upload it back through the server manager, then load the new session. The old session can be deleted afterwards.
Why did my renamed session go back to its old name?
Something renamed only the header or only the file name. The authoritative copies live inside the compressed save state as mSaveSessionName and mReplicatedSessionName; on the next save the game rewrites the header from those, restoring the old name. A rename only sticks when the compressed properties change too, which is exactly what this editor does.
Which game versions does it support?
Renaming supports saves written by Update 8 and everything after it, including 1.0, 1.1 and 1.2. Older saves still get the read-only inspection; load them once in the current game so they are rewritten in the modern format, then rename. Output files are re-validated structurally before download.
Does my save get uploaded?
No. The file is read, decompressed, edited and recompressed by JavaScript running in your browser tab. There is no upload endpoint on this page, which also means a 500 MB endgame save works as well as a fresh one, with no waiting on a server.