Don't Starve uses a local profile/world directory distinct from Don't Starve Together. Back up the full DoNotStarve folder and keep workshop/mod information with long-running worlds.
For this PC reference, the documented storage is Windows: %USERPROFILE%DocumentsKleiDoNotStarve. The known file or folder pattern is profile/save records under the Klei DoNotStarve directory. Don't Starve keeps desktop progress in a Klei Documents tree. Mods and world generation can affect compatibility, so preserve the whole directory and the active mod context.
Backup guidance: Close Don't Starve, let the launcher finish any synchronization, then copy the complete documented save directory to a dated folder outside the live path. Preserve companion files rather than selecting only the newest-looking record. Steam Cloud can synchronize profile/save data depending on configuration; keep an offline Klei folder copy before changes. Launcher and cloud context matters because The active Steam installation determines which local profile and cloud copy can overwrite the save. Identify the storefront and account before restoring files.
Compatibility and recovery should stay conservative. Treat saves as version-, storefront-, account-, and mod-sensitive unless the game or a separately verified migration workflow proves otherwise. A similar filename or extension is not evidence that two releases are interchangeable. If the expected progress is not visible, If progress is missing after a restore, confirm the active Windows account, storefront/profile, cloud state, and exact directory first. Restore the untouched backup before experimenting with individual files or older autosaves. SaveEditor.com only labels a game-specific editor as available when a separate linked Tool has a verified operational runtime; this reference page by itself is not an editor claim.