Satisfactory uses a consistent LocalAppData SaveGames root across Steam and Epic, but the account-ID directory underneath is important: a player who switched storefronts can have more than one valid subfolder. SaveEditor recommends comparing timestamps and preserving all relevant .sav generations rather than uploading or editing the first file found. This is also a format-version-sensitive game, so an external calculator saying “unsupported save version” can simply mean that tool has not caught up with a new game build.
Identify the exact save you intend to edit
The researched Satisfactory PC save location is Windows: %LOCALAPPDATA%FactoryGameSavedSaveGames<account-id>. Known file/folder pattern: *.sav files; the filename normally reflects the save/session name, with multiple autosave/manual versions possible.. Storefront context: Steam, Epic Games Launcher. Steam and Epic can create different account-ID subfolders under the same root. Selecting the wrong folder can make the correct .sav look missing. Do not edit a similarly named file from a different profile, edition, or cloud cache.
Make an untouched backup first
Back up the complete account-ID folder, not just the latest autosave. Keep several generations before moving between Early Access/Experimental/current builds or using an external calculator/editor. Keep that copy outside the live save directory and do not overwrite it with later experiments. Cloud context: Steam Cloud and Epic cloud are documented. Cloud conflicts are especially relevant when switching machines or branches. If a launcher can synchronize the save, prevent it from silently replacing either the original or edited copy while testing.
Understand the format boundary
Steam and Epic use the same SaveGames root but place saves in account-ID subfolders. The game format changes across builds, so external tools may lag behind the current save version. File-extension context: .sav Compatibility note: A third-party tool rejecting a .sav can mean the tool has not yet added the current Satisfactory save version; it does not prove the game file itself is corrupt. These facts help identify the save but do not automatically reveal every field, checksum, encryption rule, or version-specific structure inside it.
Use only a Tool whose claim matches the file
Generic viewers and diff tools can inspect bytes without claiming game-specific semantics. A game-specific editor should be used only when its Tool page explicitly lists Satisfactory, a matching supported version/container, and a Verified operational runtime. A planned URL or Game Hub is not evidence that an editor exists.
Test the edited copy safely
Write to a new output file when the Tool supports it, keep the original backup, restore the edited copy into the correct profile/storefront location, and launch the game only after the file operation finishes. If the game rejects it, If the expected .sav is absent, look one level below SaveGames for all account-ID folders and compare timestamps. If an external parser rejects it, test the save in the game before diagnosing damage. Return to the untouched backup before trying another change.
Verification context: Reviewed against current PCGamingWiki and Official Satisfactory Wiki save-file documentation, including the account-ID subfolder and current cloud-conflict guidance.