Stardew Valley is a good example of why backing up a folder is safer than hunting for a single extension. A farm lives in its own directory, and the directory contains multiple related records. That makes the folder boundary the practical unit for backups. On Windows, macOS, and Linux the path is well documented and easy to copy once hidden application-data folders are visible. Before a major mod change or a manual save operation, copy the entire farm directory to a location outside the live Saves folder and give the copy a date.
Prepare the source PC
On the source system, identify the actual Stardew Valley save root: Windows: %APPDATA%StardewValleySaves | macOS: $HOME/.config/StardewValley/Saves/ | Linux / Steam Play: $XDG_CONFIG_HOME/StardewValley/Saves/ (normally ~/.config/StardewValley/Saves/). The expected file/folder pattern is <FarmName>_<unique-id>
SaveGameInfo. Close the game, let the active launcher finish writing and synchronizing, then make a complete offline copy rather than transferring a file that may still be open.
Preserve storefront and profile identity
Documented storefronts: Steam, GOG Galaxy, Xbox / Microsoft Store. The normal desktop save folder is shared by Windows builds that use the standard StardewValley application-data path, while Microsoft Store/Xbox packaging and cloud behavior can differ. Do not assume a console or mobile save can be copied directly into the desktop folder. A transfer between two PCs is simplest when both systems use the same storefront/account/profile context. If the destination uses a different store or container, treat that as a migration problem rather than an ordinary restore.
Move the complete save boundary
Copy the whole farm folder, not only one file. This preserves the main save, SaveGameInfo, and any paired backup files that may be useful for recovery. Put the copied data on the destination only after confirming the destination save path. If the game creates a new empty save first, keep that new folder as another backup so you can compare structures and revert.
Handle cloud sync deliberately
Steam Cloud and GOG Galaxy cloud support are documented. Cloud sync is convenient but should not replace a dated offline copy before mods, save editing, or migration. Decide whether the local transferred copy or cloud copy should be authoritative before launching the game. If possible, preserve both. After the transferred save loads correctly, make a fresh in-game save and let the launcher synchronize normally.
Check compatibility before blaming the transfer
Each farm is stored as a folder. Standard desktop saves include the main farm save and SaveGameInfo; the main data is XML text even though the primary file normally has no conventional extension. Compatibility note: Desktop saves are structured farm folders. Modded saves may depend on content or IDs provided by installed mods, so restoring the file without the same mod set can change behavior. If the destination does not see the transferred progress, If a farm disappears from the load menu, compare the folder name, the main save filename, and SaveGameInfo. Keep the original folder intact before trying older backup copies. Verify game edition/version, store, profile IDs, redirected folders, and mod/DLC dependencies before editing the save itself.
Verification context: Desktop save paths and cloud services were reviewed against current PCGamingWiki coverage. File-structure notes are limited to the standard farm-folder layout; no arbitrary XML rewrite is performed by this Game Hub.