Complete Factorio Server Hosting Guide: Setup, Configuration, and Performance

Why Host a Dedicated Factorio Server?

Factorio multiplayer uses a lockstep simulation model. Every player’s client runs the exact same simulation, and the server acts as the authoritative coordinator. A dedicated server means no single player’s machine is the bottleneck. The factory runs 24/7, players can join and leave freely, and performance stays consistent regardless of the host player’s hardware.

Whether you are running a vanilla megabase or a modded Space Age playthrough, this guide covers everything you need to set up a Factorio server.

Hardware Requirements

Factorio is CPU-bound and single-threaded for the simulation. Requirements scale with factory size, not player count.

Player Count	RAM	CPU	Notes
1-4 players	2 GB	Dual-core	Sufficient for early to mid-game
5-12 players	4 GB	Quad-core	Handles moderate factories
12+ players	8 GB	Quad-core, fast single-thread	Required for megabases (1000+ SPM)

Storage requirements are modest. The server binary is small, and save files typically range from 10-100 MB depending on factory size. SSD storage is recommended for faster save and load times.

Self-Hosting: Step by Step

Step 1: Download the Headless Server

Factorio provides a free headless server binary. You do not need to own the game to run a server.

Linux (most common for servers):

wget https://factorio.com/get-download/stable/headless/linux64
tar -xf linux64

Windows: Download the dedicated server package from factorio.com. The headless binary is also available through Steam.

Step 2: Create a Save File

The server needs an existing save to load. Generate one from the command line:

./factorio --create ./saves/my-save.zip

This creates a new default map. You can also copy an existing single-player save into the saves directory.

Step 3: Configure Server Settings

Copy server-settings.example.json to server-settings.json and edit it:

{
  "name": "My Factory",
  "description": "A Factorio server hosted for friends",
  "visibility": { "public": false, "lan": true },
  "game_password": "your-secure-password",
  "max_players": 10,
  "autosave_interval": 5,
  "autosave_slots": 5,
  "require_user_verification": true
}

Key settings to configure:

• name and description: Identify your server in the server browser.
• visibility: Set public to true if you want the server listed in the in-game browser. Keep it false for private sessions.
• game_password: Protects access. Always set this for private servers.
• autosave_interval: Minutes between automatic saves. Default is 5, which works well for most setups.
• require_user_verification: When true, players must have a verified Factorio account. Keeps out pirated copies.

Step 4: Configure the Network

Factorio uses UDP port 34197 by default. This is the only port you need to forward.

If self-hosting behind a router:

1. Assign your server a static local IP.
2. Forward UDP port 34197 to that IP in your router settings.
3. Open port 34197 in your OS firewall.

Players connect via Multiplayer, then “Connect to address” using your public IP and port.

Step 5: Start the Server

./factorio --start-server ./saves/my-save.zip --server-settings ./server-settings.json

The server will load the save and begin listening for connections. Use --console-log to write logs to a file for troubleshooting.

Managing Mods

Factorio’s mod support works seamlessly in multiplayer, but every player must have the exact same mods and versions installed.

Server-Side Mod Installation

Place mod .zip files in the mods directory next to the server binary. Create or update mod-list.json to enable the mods you want.

Client Synchronization

When a player connects, the game compares their mod list with the server. If “Sync mods with server” is enabled in the server browser, the client automatically downloads the correct mod versions. This is the recommended approach and prevents most desync issues.

Mod Compatibility With Space Age

Since the Factorio 2.0 update, many popular mods have been updated for compatibility. If you are running Space Age content, verify that each mod explicitly supports version 2.0. Using outdated mods is the most common cause of desynchronization errors.

Managed Hosting: Skip the Setup

Self-hosting requires a dedicated machine, network configuration, and ongoing maintenance. A managed hosting provider eliminates all of this.

With Reactor’s Factorio hosting, you get:

• Instant setup: Server is ready in minutes, no command-line work required.
• Optimized performance: Enterprise hardware tuned for Factorio’s single-threaded simulation. Handles megabases with 1000+ SPM smoothly.
• Automatic mod sync: Mod management built into the server.
• 24/7 uptime: Your factory never stops, even when all players are offline.
• SFTP access: Upload saves, manage mods, and configure settings directly.
• Automatic backups: Regular backups protect against save corruption.

Troubleshooting Common Issues

Desync Errors

Desynchronization means the server and a client disagree on the game state. This is almost always caused by incompatible mods, not network issues. Solutions:

1. Enable “Sync mods with server” in the server browser.
2. Verify every mod version matches exactly between server and all clients.
3. If desyncs persist, start the server with --check-consistency to force verification.

Connection Timeout

If players cannot connect, verify:

• UDP port 34197 is forwarded and open in your firewall.
• The server is actually running (check the console output).
• Players are using the correct public IP and port.

Save Corruption

Rare but possible after crashes. This is why autosaves with multiple slots are essential. If your primary save is corrupted, load the most recent autosave.

Get Your Factory Online

A dedicated Factorio server is the best way to build with friends. No lag from the host player’s connection, persistent factory operation, and reliable multiplayer.

Start a Factorio server with Reactor and grow the factory together.