The Sims 4 already keeps several recovery generations next to each main slot, which makes indiscriminate cleanup a mistake. A good backup preserves the whole saves directory, including `.save.ver0` through `.ver4` files. If a slot becomes unusable, duplicate the directory first and test recovery on the copy. Also remember that the Documents tree may be redirected or synchronized by OneDrive, so the file you replace locally may not be the only copy involved.
Known The Sims 4 save-file structure
The researched filename or folder pattern is Slot_*.save
Slot_*.save.ver0 … .ver4. File-extension context: .save, .save.ver0, .save.ver1, .save.ver2, .save.ver3, .save.ver4 The documented format notes are: The game maintains main Slot_*.save files and several rotating .save.verN recovery copies. These historical versions are valuable rollback points and should be preserved before manual recovery.
Why an extension is not enough
A save filename can identify a likely container, but it does not prove the internal schema, game version, checksum rules, encryption state, or editability. The save can depend on installed packs, custom content, and mods. Missing content after migration is not the same as binary save corruption. SaveEditor therefore separates file identification from Tool compatibility and only labels a game-specific Tool Verified when its exact profile/version evidence passes the runtime gate.
Where the format is stored
PC save locations: Windows: %USERPROFILE%DocumentsElectronic ArtsThe Sims 4saves | macOS: $HOME/Documents/Electronic Arts/The Sims 4/saves/ | Linux / Steam Play: Steam Play: <SteamLibrary-folder>/steamapps/compatdata/1222670/pfx/. Storefront context: EA app, Steam, Epic Games Launcher. The active Windows saves still live under Documents/Electronic Arts. Steam and Epic launch through EA services but should not be assumed to maintain a separate independent save directory. This matters because two releases can use different containers or companion files even when the visible slot name is similar.
Back up before inspecting or editing
Copy the complete saves directory so each main slot and its .ver0-.ver4 recovery generations remain together. A read-only viewer is lower risk than a writer, but the live save should still be copied first. Cloud context also matters: OneDrive Documents backup can synchronize or redirect the saves directory when enabled. Treat that as a second copy source when diagnosing unexpected restores. Keep the original bytes available so any experiment can be reversed without relying on a cloud service or automatic backup.
What this reference does not claim
This page does not infer an undocumented checksum algorithm, encryption key, compression layer, or cross-store conversion from the file extension. Troubleshooting evidence: If a main Slot file fails, preserve it first, then work from a copied .save.verN generation. Do not rename over every version until one recovery copy has been tested. Those questions require a verified parser/profile or a game-specific source, not a generic format guess.
Verification context: Windows/macOS/Steam Play save paths and storefront/OneDrive context were reviewed against current PCGamingWiki coverage. Rotating Slot recovery filenames follow the standard Sims 4 desktop layout.