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Save Sync Guide

Save Sync keeps your game saves synchronized between your RomM server and your handheld device.

Sync Modes

Grout offers two sync modes, configurable in Settings:

Manual Mode

  • Press Y from the main menu to access save sync
  • You control when syncing happens
  • A sync summary is displayed after completion

Automatic Mode

  • Grout automatically syncs saves in the background when you launch the app
  • A cloud icon appears in the status bar showing sync progress:
    • Cloud with up arrow - Upload in progress
    • Cloud with down arrow - Download in progress
    • Cloud with checkmark - Sync completed successfully
    • Cloud with an exclamation mark - Something went wrong, check the logs

How It Works

When you run Save Sync, Grout:

  1. Scans your device for games and their save files
  2. Matches them with corresponding ROMs in RomM
  3. Compares local and remote save files
  4. Syncs saves based on which version is newer

ROM Matching

For Save Sync to work, Grout must match your local ROM files with ROMs in your RomM library. Grout uses several methods to find matches, tried in order:

1. Filename Match

If the local ROM filename (without extension) exactly matches a ROM's filename in RomM, it's considered a match. This is the fastest and most common matching method.

2. Hash Match

If filename matching fails, Grout can compute the CRC32 or SHA1 hash of your local ROM file and compare it against hashes stored in RomM. This is useful when:

  • Your local ROM has a different filename than in RomM
  • You renamed a ROM locally, but it's the same file

3. Fuzzy Title Match

If both filename and hash matching fail, Grout attempts to match based on title similarity. This helps when ROM names differ slightly between your device and RomM.

What fuzzy matching handles:

  • Accented characters - "Pokemon Red" matches "Pokemon Red"
  • User-added suffixes - "Pokemon Red Nuzlocke" matches "Pokemon Red Version" (both share "Pokemon Red" as a common prefix)
  • Naming convention differences - "Pokemon - Red Version" matches "Pokemon Red"

When a potential match is found with at least 80% similarity, Grout displays a confirmation prompt:

+-------------------------------------+
|  Potential Match Found              |
|                                     |
|  Local: "Pokemon Red Nuzlocke"      |
|  Match: "Pokemon Red Version"       |
|  Similarity: 85%                    |
|                                     |
|  Is this the same game?             |
|                                     |
|  [B] No    [X] Yes                  |
+-------------------------------------+
  • Press X to confirm the match
  • Press B to decline

Confirmed matches are remembered - once you confirm a fuzzy match, Grout saves the association and won't ask again for that ROM. This is useful for maintaining separate saves (like a Nuzlocke run alongside a regular playthrough).

Declined matches have a cooldown - if you decline a fuzzy match, Grout won't prompt you again for 24 hours.

Tip

When you refresh the games cache, any saved matches for ROMs that no longer exist in RomM are automatically cleaned up.

Sync Logic

For each mapped ROM file found on your device, Grout determines what action to take:

When RomM has no save

Your local save, if present, is uploaded to RomM (with timestamp appended to filename).

When you have no local save

RomM's save, if present, is downloaded to your device.

When both saves exist

The newer save (based on last modified time) determines the action:

  • If the local save is newer: It is uploaded to RomM with the last modified timestamp appended to the filename
  • If the RomM save is newer:
    • The current local save is backed up to .backup/ within the platform's save directory
    • The RomM save is downloaded to your device

No matching ROM in RomM

The save file is reported as "unmatched" in the sync results.

Important

The filename of the save will match the local filename of the ROM. This will allow you to have a ROM file duplicated locally under two names to handle two different saves (e.g. a Nuzlocke run in Pokemon alongside a vanilla playthrough).

Sync Results

After syncing, you'll see a summary showing:

  • Downloaded saves - Saves transferred from RomM to your device
  • Uploaded saves - Saves transferred from your device to RomM
  • Unmatched saves - Local saves without corresponding ROMs in RomM
  • Errors - Any problems that occurred during sync

Per-Game Save Directory

Some platforms have multiple emulators available (e.g., GBA on muOS). By default, Grout uses the platform-wide save directory configured in Save Sync Mappings.

You can override this for individual games:

  1. Open the game in Game Details view
  2. Press Y to open Game Options
  3. Change the Save Directory setting

When you change this setting, Grout automatically moves existing save files to the new location.

Important

Kids Mode Impact: When Kids Mode is enabled, the Game Options screen is hidden. You won't be able to change per-game save directories while Kids Mode is active.

Important Notes

Save files only

Save Sync works with save files, NOT save states. Save states are emulator-specific snapshots that require both sides to use the same emulator and sometimes even the same version.

Syncs can be obscured by autoload

If you use save states with autoload enabled, the emulator will load the state instead of the save file. To use synced saves:

  • Use the in-game menu to reset the emulator, forcing the save to be used
  • Disable autoload for save states
  • Delete the save state after downloading a synced save

User-specific

Saves are tied to your RomM user account. If you share your RomM account with others, your saves will also be shared.