How to Set Up a Factorio Multiplayer Server

Factorio's multiplayer lets you and your friends collaborate on massive factory designs, from spaghetti starter bases to megabases producing thousands of science per minute. A dedicated server keeps your factory running 24/7, letting players drop in and contribute on their own schedule. This guide covers setup, save management, and performance optimization.

What You'll Need

• Factorio purchased — Every player needs the game (Steam or standalone).
• A hosting plan or spare machine — Managed hosting starts at $4-6/month. Factorio is lightweight early-game but scales with factory complexity.
• A game plan — Vanilla, modded, or Space Age expansion? Decide before setup.

Step 1: Choose Your Hosting Approach

Managed Hosting (Recommended)

Factorio servers start lightweight but CPU usage scales with factory size. Managed hosts like Sparked Host, Nodecraft, and Shockbyte offer:

• Scalable resources — Upgrade as your megabase grows
• Simple mod management — Upload mod files through the control panel
• Automatic saves — Never lose factory progress
• Low latency — Important for real-time belt and train synchronization

Self-Hosted

Download the headless server from factorio.com (no Steam required). Forward port 34197 (UDP). Factorio's dedicated server runs on Windows, Linux, and macOS — Linux is recommended for best performance.

Step 2: Set Up on a Managed Host

1. Purchase a plan — 2GB RAM handles most factories. Megabases with 1000+ SPM may need 4GB.
2. Select Factorio as your game.
3. Upload your save file or start a new map.
4. Configure server settings in the control panel.
5. Start the server and connect via Direct Connect in the Factorio multiplayer menu.

Step 3: Configure server-settings.json

The main configuration file for your Factorio server:

{
  "name": "My Factorio Server",
  "description": "Collaborative factory building",
  "tags": ["vanilla", "cooperative"],
  "max_players": 0,
  "visibility": {
    "public": true,
    "lan": true
  },
  "username": "YourFactorioUsername",
  "password": "",
  "token": "YourAuthToken",
  "game_password": "",
  "require_user_verification": true,
  "max_upload_in_kilobytes_per_second": 0,
  "max_upload_slots": 5,
  "minimum_latency_in_ticks": 0,
  "ignore_player_limit_for_returning_players": false,
  "allow_commands": "admins-only",
  "autosave_interval": 10,
  "autosave_slots": 5,
  "afk_autokick_interval": 0,
  "auto_pause": true,
  "only_admins_can_pause_the_game": true
}

Key Settings

| Setting | Default | Description | |---|---|---| | auto_pause | true | Pause when no players online | | autosave_interval | 10 | Minutes between autosaves | | allow_commands | admins-only | Console command access | | max_upload_slots | 5 | Concurrent map download slots | | afk_autokick_interval | 0 | Kick AFK players (0 = disabled) |

Step 4: Map Generation Settings

Control world generation with map-gen-settings.json:

{
  "terrain_segmentation": 1,
  "water": 1,
  "width": 0,
  "height": 0,
  "starting_area": 1,
  "peaceful_mode": false,
  "autoplace_controls": {
    "coal": { "frequency": 1, "size": 1, "richness": 1 },
    "iron-ore": { "frequency": 1, "size": 1.5, "richness": 1.5 },
    "copper-ore": { "frequency": 1, "size": 1.5, "richness": 1.5 },
    "stone": { "frequency": 1, "size": 1, "richness": 1 },
    "uranium-ore": { "frequency": 1, "size": 1, "richness": 1 },
    "crude-oil": { "frequency": 1, "size": 1.5, "richness": 2 }
  },
  "pollution": {
    "enabled": true
  }
}

Tip: For megabase planning, increase ore richness to 2-3 so patches last longer. Set starting_area to 2 for a more relaxed early game.

Step 5: Install Mods

Place mod .zip files in the server's mods/ directory. Create or edit mod-list.json:

{
  "mods": [
    { "name": "base", "enabled": true },
    { "name": "quality", "enabled": true },
    { "name": "space-age", "enabled": true },
    { "name": "even-distribution", "enabled": true }
  ]
}

All players must have matching mods installed. Popular multiplayer mods:

| Mod | Purpose | |---|---| | Even Distribution | Evenly distribute items across machines | | Bottleneck Lite | Show machine status indicators | | Rate Calculator | Calculate production rates | | Squeak Through | Walk between buildings | | FNEI | Recipe browser |

Important: All players must have the exact same mod versions as the server. Factorio enforces strict mod matching.

Step 6: Admin Commands

Use the in-game console (~ key) or RCON for remote commands:

| Command | Description | |---|---| | /admin PlayerName | Grant admin rights | | /ban PlayerName | Ban a player | | /unban PlayerName | Unban a player | | /kick PlayerName | Kick a player | | /save | Force a manual save | | /evolution | Check biter evolution factor |

RCON Setup

Enable RCON in the server launch command for remote administration:

--rcon-port 27015 --rcon-password YourRCONPassword

Step 7: Performance Optimization

Factorio servers are single-threaded and CPU-bound. As factories grow, UPS (Updates Per Second) becomes the key metric:

• Target: 60 UPS (game runs at full speed)
• Warning: Below 50 UPS, gameplay feels noticeably sluggish

Performance Tips

• Use belts over bots for bulk transport at megabase scale
• Limit active radar coverage — each radar chunk costs CPU
• Minimize pollution spread with efficiency modules
• Use train networks for long-distance transport instead of very long belts
• Disable biter expansion (/c game.map_settings.enemy_expansion.enabled=false) if performance matters more than combat

Troubleshooting Common Issues

Players can't connect:

• Verify port 34197 (UDP) is open.
• Check that username and token are set in server-settings.json for public visibility.
• Ensure game versions match between server and client.

UPS dropping below 60:

• Check the debug overlay (F4) for the biggest CPU consumers.
• Reduce active chunk count by limiting exploration.
• Consider switching to a host with stronger single-thread CPU performance.

Mod mismatch errors:

• All players must have the exact same mod versions.
• Share your mod-list.json with players or use a mod portal sync.
• Server logs show which mods are mismatched.

Next Steps

• Set up a shared mod pack so all players have matching mods.
• Plan factory layouts using tools like Factorio Planner or Kirk McDonald's calculator.
• Create a Discord with channels for base planning and logistics coordination.
• Schedule upgrade windows to update mods and Factorio versions together.

Factorio's multiplayer is incredibly rewarding when the logistics come together. Hosts like Sparked Host and Nodecraft provide the single-thread CPU performance that keeps your megabase running at full 60 UPS.