Subnautica’s save unit is a slot directory. Each slot contains several records describing world and player state, which means a backup made from one selected file can be incomplete. The safest procedure is to close the game and copy the entire `SavedGames` directory or the complete slot you care about. Storefront matters because the base path can change—particularly between the standard game directory and the Epic LocalLow location.
Identify the exact save you intend to edit
The researched Subnautica PC save location is Windows: Standard Windows: <path-to-game>SNAppDataSavedGames
Epic: %USERPROFILE%AppDataLocalLowUnknown WorldsSubnauticaSubnauticaSavedGames | macOS: $HOME/Library/Application Support/unity.Unknown Worlds.Subnautica/Subnautica/SavedGames | Linux / Steam Play: Steam Play: <SteamLibrary-folder>/steamapps/compatdata/264710/pfx/. Known file/folder pattern: slot0000, slot0001, … save directories. Storefront context: Steam, Epic Games Launcher, Microsoft Store / Xbox app. PCGamingWiki documents different Windows locations for standard installs and Epic. Microsoft Store packaging should be treated separately when the standard SNAppData path is absent. Do not edit a similarly named file from a different profile, edition, or cloud cache.
Make an untouched backup first
Copy complete slot directories or the entire SavedGames folder. Do not back up only the most obvious binary file inside a slot. Keep that copy outside the live save directory and do not overwrite it with later experiments. Cloud context: Cloud support depends on storefront. The local slot directory should still be backed up before game updates, mods, or migration. If a launcher can synchronize the save, prevent it from silently replacing either the original or edited copy while testing.
Understand the format boundary
Subnautica uses slot directories rather than one portable save file. A slot contains multiple binary/metadata records, so preserving the full slot folder is safer than selecting one .bin file. File-extension context: .bin, .json Compatibility note: A slot folder is a coordinated set of files. Mixing parts from different slot revisions can create a state that was never produced by the game. 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 Subnautica, 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 SNAppData directory is empty, identify the storefront and check the documented Epic LocalLow path. Keep older slot copies intact while diagnosing. Return to the untouched backup before trying another change.
Verification context: Standard Windows, Epic, macOS, and Steam Play locations were reviewed against current PCGamingWiki coverage.