tModLoader transforms Terraria into an endlessly expandable experience. With mods like Calamity, Thorium, and Magic Storage, your modded Terraria world becomes a massive project - new bosses, new biomes, new crafting systems, and hundreds of hours of content. Playing that co-op with friends is the best way to experience it.

The catch: just like vanilla Terraria multiplayer, the host owns the world save. When they are offline, nobody else can continue. And in a modded playthrough that can easily span weeks or months, host availability becomes a real bottleneck.

Where Does tModLoader Save Worlds and Players?

tModLoader stores its saves in a separate folder from vanilla Terraria - it never touches your vanilla worlds. On Windows:

Documents\My Games\Terraria\tModLoader\Worlds\    (your .wld world files)
Documents\My Games\Terraria\tModLoader\Players\   (your .plr characters)

Each world is a .wld file with extra modded data in a matching .twld file, plus .bak backup copies the game keeps in case of corruption. (Vanilla Terraria uses Documents\My Games\Terraria\Worlds - a different folder tModLoader does not use.)

Saving works like Terraria: the game autosaves periodically (community-reported around every 10 minutes, and you can toggle autosave in settings), and choosing Save & Exit from the menu saves both your world and character. Your character is also force-saved on death.

What saving can’t do on its own is get that world onto a friend’s PC. In co-op the world lives only on the host’s machine - which is the gap SaveSync closes.

How SaveSync Keeps Your Modded World Accessible

SaveSync syncs your tModLoader world and player saves across every member of your co-op group. After each session, the save files are automatically distributed. The next time anyone wants to play, they can host the world themselves with the most recent progress.

No server hosting. No file juggling. Just synced saves.

How to Set Up SaveSync for tModLoader

  1. Install SaveSync from Steam. Every player in your group needs it.
  2. Create a sync group and invite your Terraria crew.
  3. Locate the tModLoader save directory. tModLoader stores worlds separately from vanilla Terraria - typically in Documents/My Games/Terraria/tModLoader/Worlds/. Point SaveSync to your shared world files.
  4. Play your sessions as normal. Host through the in-game multiplayer menu using “Host & Play.”
  5. SaveSync syncs automatically when the world save updates.
  6. Any player can host next. Load the synced world in tModLoader and invite the group.

Why Use SaveSync Instead of Terraria Dedicated Server or Manual Sharing

tModLoader does support a dedicated server mode, but it comes with limitations that SaveSync avoids:

  • Mod compatibility. Running a tModLoader dedicated server requires careful mod management on the server side. With SaveSync, every player runs the mods locally through tModLoader’s own mod browser, which is simpler and more reliable.
  • Server performance. Modded Terraria can be resource-intensive. A dedicated server needs enough power to handle modded world generation, boss fights, and events. With SaveSync, the host runs the world on their own machine where performance scales naturally with their hardware.
  • Cost. Renting a server with enough performance for heavily modded Terraria is not cheap. SaveSync has no recurring costs.
  • Manual file sharing is risky. tModLoader world files are linked to specific mod versions. Sending files through Discord without tracking which version of the world corresponds to which mod loadout leads to corruption and crashes. SaveSync handles versioning automatically.

For small friend groups playing through a modded run together, SaveSync is the most straightforward solution.

Defeat Every Modded Boss Together

Whether you are facing Supreme Calamitas, building an elaborate Magic Storage network, or exploring Thorium’s depths, your modded Terraria playthrough deserves continuity. SaveSync makes sure the world is always available, so progress never stalls because of one person’s schedule.