The FTB App (Feed The Beast) is the official launcher for browsing and installing FTB and CurseForge modpacks. It’s a go-to for groups who play big modded packs together. But like every launcher, it leaves one thing unsolved: the world save lives on one player’s machine.

Play a modpack together through “Open to LAN” and the world only exists while the host is online. A dedicated server fixes that but costs money and needs upkeep. This guide covers where the FTB App keeps your worlds, whether it can host a server, and how to share saves so anyone can host.

Can the FTB App Host a Server?

Not by itself - the FTB App is a client launcher. It installs and launches modpacks, but the app doesn’t run a dedicated server. FTB does provide a separate Server Installer (a standalone download you run yourself) for people who want a full server. Your real options for co-op are:

  • Open to LAN - launch a pack, press Esc -> Open to LAN, and friends on your network join. Only runs while your game is open.
  • The FTB Server Installer - download and run the matching server files outside the app. That means maintaining a 24/7 machine or paying a host.
  • Save sharing - skip the server: pass the world save between players so whoever’s around can host it locally. That’s this guide’s approach.

Where Does the FTB App Save Worlds?

The FTB App keeps each modpack as its own instance. On Windows, the instances root is:

%LOCALAPPDATA%\.ftba\instances\

Inside each instance, the world saves live in the pack’s Minecraft folder:

%LOCALAPPDATA%\.ftba\instances\<InstanceID>\minecraft\saves\<WorldName>\

Instance folders are usually named by an ID rather than the pack name. The reliable way to find the right one: in the app, select the pack, choose “Edit Instance” (or the settings/folder option) -> “Open Folder,” then open the saves subfolder. Each world is its own folder with level.dat and region data. (You can also change the instance location under Settings -> Instances.)

How SaveSync Bridges the Gap

SaveSync synchronizes your Minecraft world save across every player in your group. When the host finishes, SaveSync pushes the save to everyone. Next session, whoever’s around loads the world and opens it to LAN for the rest. No server, no monthly fees - just shared worlds.

How to Set Up SaveSync for the FTB App

  1. Install SaveSync from Steam. Every player needs it.
  2. Create a sync group and invite your friends.
  3. Locate your world folder (%LOCALAPPDATA%\.ftba\instances\<InstanceID>\minecraft\saves\, via “Open Folder” on the instance). Point SaveSync at the world you want to share.
  4. Play normally. Host through Open to LAN.
  5. SaveSync syncs the world to everyone when the session ends.
  6. Anyone can host next time from their own copy of the pack.

Why Use SaveSync Instead of a Dedicated Server

  • No hosting fees. A modded server with enough RAM runs $10-20/month or more. SaveSync is a one-time purchase.
  • Nothing to maintain. No server updates, uptime, or backups to manage.
  • Everyone runs the same pack locally. Install the identical FTB modpack in your own launcher - no client-vs-server mismatch to debug.
  • Right-sized for friends. For a small group sharing one world, a dedicated server is more than you need.

For large public communities, a dedicated server still makes sense. For a friend group with a shared modded world, SaveSync is simpler and cheaper.

Your Modpack World, Available to Everyone

The FTB App already makes installing huge modpacks effortless. SaveSync adds the last piece - keeping the world itself from being stuck on one player’s machine. Share the save, share the hosting, and keep building.