Short answer. You can host a RimWorld Together server yourself for free: download the server zip for your system from the project's GitHub releases (for example Server-linux-x64.zip), extract it into its own folder, run the RTServer executable and forward TCP port 25555 on your router. Or rent a RimWorld Together server and skip the networking.

Players join from the RimWorld main menu with the RimWorld Together mod enabled, by typing your IP address and port 25555, or by finding the server in the in-game server browser, where the current release lists servers by default.

Checked on 5 November 2026, accurate for release 26.11.2.1 (2 November 2026). Server and mod must match, so check the version again before you invite people.

This guide uses the RimWorld Together GitHub repository (README and server source code at release 26.11.2.1) and the project's wiki, plus what we run on our own RimWorld Together servers. To go straight to the rental route, see Option 2.

What you need

Operating system: the releases include server builds for Linux (x64, arm64, arm) and Windows (x64, x86). The wiki says macOS is not supported.
Hardware: the project says there are no heavy hardware requirements and that the machine mostly needs excellent network bandwidth.
Network: TCP port 25555 by default, reachable from the internet if players are not on your network. The server listens on TCP only.
Steam account: not needed for the server. It is a single program from GitHub, not a Steam download.
The game: every player needs RimWorld with the free RimWorld Together mod from the Steam Workshop (item 3005289691), at exactly the same version as the server. The server refuses a client whose version differs.

The server software is free. You pay for the machine, power and bandwidth, not the software.

Option 1: host it yourself

This works on a spare PC, a home server or a cloud virtual machine. The steps follow the project's README, wiki and server code.

Linux

Download and extract the server into its own folder, because the server creates many files and folders next to itself.

sudo apt install -y curl unzip
mkdir ~/rwt-server && cd ~/rwt-server
curl -L -O https://github.com/RimWorld-Together/Rimworld-Together/releases/latest/download/Server-linux-x64.zip
unzip Server-linux-x64.zip

Use Server-linux-arm64.zip or Server-linux-arm.zip on those processors.

Make it executable and start it.
```
chmod +x RTServer
./RTServer
```
The server creates its Configs folder with the settings files the first time it runs. Avoid putting it in a location that needs administrator rights. The README warns that antivirus or the system may block it there.
Stop it and open the settings. Configs/ServerConfig.json holds the basics. The main keys and their defaults in this release:
```
Name: "RimWorld Together Server"
Description: "Welcome to our RimWorld Together server!"
IP: "0.0.0.0"
Port: 25555
MaxPlayers: 100
EnableServerBrowser: true
UseUPnP: false
```
Name and description are what the server browser shows. UseUPnP set to true makes the server try to open its port on your router by itself, which only works if the router has UPnP switched on.
Open the port. Allow TCP 25555 on the machine's firewall (with ufw: sudo ufw allow 25555/tcp), then create a TCP port forward for 25555 on your router that points at the machine's local IPv4 address.
Start the server again and test the join from the same machine first: in RimWorld, connect to 127.0.0.1 and port 25555. Then ask a friend outside your network to connect to your public IP.

Windows

Download Server-win-x64.zip from the latest release and extract it into its own folder (use Server-win-x86.zip on 32-bit Windows).
Run RTServer.exe. A terminal window opens and starts the server.
Allow TCP 25555 inbound in Windows Firewall and forward TCP 25555 on your router, as in the Linux step 4.

With Docker

The project publishes an official container image. Create a data folder, then run it with the port mapped:

mkdir -p RWTData
docker run -it --rm -v './RWTData:/Data' -p 25555:25555 ghcr.io/rimworld-together/rimworld-together:latest

Becoming an admin and the world

The first player to join creates the world for everyone. The wiki recommends generating it with all the mods you plan to use. Storytellers, difficulty and scenarios can be changed afterwards.
To become an admin, join once so your user exists, then type deeplist in the server console to list the usernames and op followed by yours, for example op YourName. The wiki says you then turn on RimWorld's dev mode in game to open the admin menu. Our guide How to Become an Admin on Your RimWorld Together Server has the panel version.
Other files in Configs include ModConfig.json, BackupConfig.json, ChatConfig.json (join messages and a message of the day), DifficultyConfig.json, ScenarioConfig.json and StorytellerConfig.json. The Configs/Actions folder holds one file per feature, such as Raid.json, Trade.json and Caravan.json.
The server lists itself in the in-game browser by default (EnableServerBrowser is true) and finds its own public address. To keep a private group private, set a join password with setpassword in the console, or set EnableServerBrowser to false (the togglebrowser command flips it).

Option 2: host it on PlayNHost

Renting removes the router, the firewall and the update routine. The port and the player limit are set up for you.

Pick a plan. Open the RimWorld Together server hosting page and compare the plans (NEOLITHIC, SPACER and ARCHOTECH at the time of writing, for 20, 45 and 100 players). Press Create Server on NEOLITHIC or SPACER, or Customize Plan on ARCHOTECH, and finish the order. Prices change, so check them on that page.
Wait for the install. You get an email when it is ready, and the server appears at panel.playnhost.com. On the Console tab, the panel counts the server as running when it prints Server launched.
Find your address. The Ports & Network page shows the address and port to give your players. Do not change the port in the config files: it is the one assigned to your server.
Open Settings, then Game Settings. The main options for this game are:
- Let players join with any mods: off by default, which means a player whose mod list does not match the server's is refused. Turn it on to let players in with any mods, or none.
- Mod collection link: a steamcommunity.com link to your Steam Workshop collection. It is written into the server's SteamWorkshopURL setting, which the server sends with its entry in the in-game server browser, so players can find the right mods.
- Auto-update server and Version: see the next section.
The player limit comes from your plan, so Max Players is shown as read only.
Restart. When the panel shows "Saved. The server must restart before these take effect.", press Restart now and wait for Server launched.
Join. In RimWorld, with the mod enabled, enter the address and port from Ports & Network. The first player in creates the world.

For the settings files (name, description, backups, message of the day), open Files and the Configs folder. Our guide How to Configure Your RimWorld Together Server goes through them.

What our setup does for you

Server and mod versions stay matched. The server and the mod every player installs are built from the same release, and the server refuses a client on a different version. With Auto-update server on (the default) and Version left at latest, each start checks GitHub for the newest release and replaces the RTServer program if there is one. Your Configs folder and saved colonies are not touched. Steam updates the mod on its own schedule, so after a RimWorld Together release, restart the server and ask players to let the mod update. Typing a release number into Version pins the server to the build it has installed.
Ports and limits are written for you. At every start the panel writes IP, Port and MaxPlayers into ServerConfig.json. Hand edits to those three keys are replaced at the next start.
The mod bypass is a setting. Upstream, switching the mod check off is a console command (togglemodbypass). Here, Let players join with any mods writes the same AllowAllMods field in ModConfig.json at every start, so a console toggle does not outlast a restart.
Backups. If your plan includes backups, take one from Backups before changing the config by hand.
Public or private. The server lists itself in the in-game browser by default. For a private group, type setpassword followed by a password on the Console tab and share it with your players.

Self-hosting or renting: an honest comparison

Cost. Self-hosted: the software is free, and you pay for hardware, power and bandwidth, or a cloud virtual machine. Rented: a monthly fee set by plan. See the current plans.
Availability. Self-hosted: as reliable as your machine and home internet, and it has to be on whenever anyone wants to play, because the colonies live on the server. Rented: runs on the host's hardware, not your PC.
Network exposure. Self-hosted: players connect to your public IP and you look after the firewall and router forward. Rented: your home IP is not involved.
Skill needed. Self-hosted: unzipping, port forwarding and JSON editing. Very doable. Rented: a web panel with form fields.
Updates. Self-hosted: download the new release and replace the program yourself. Rented: Auto-update server follows the newest release at each start.

Self-hosting suits you if a machine already runs all day and you are comfortable with routers. Renting suits you if you want your group to join without depending on one person's PC. Ready to start? See the RimWorld Together plans.

Common problems and fixes

Friends cannot connect from the internet

Cause: the port forward is not active, the firewall blocks the port, or they use the wrong address.

Fix: check the port with an online port checker, allow TCP 25555 in the firewall, forward it on the router, and give them your public IP. The wiki says to allow TCP inbound and outbound on the server's port.

You cannot connect even locally

Cause: IP is misconfigured, or client and server versions differ.

Fix: set IP to 0.0.0.0, connect to 127.0.0.1 on the port in ServerConfig.json, and check that the versions match.

The server does not appear in the server browser

Cause: EnableServerBrowser or EnableServerTelemetry is set to false in ServerConfig.json, or the server is not reachable from the internet.

Fix: set both to true (the default), restart, and fix the port forward first. If others can join but you cannot, join with 127.0.0.1, since some routers do not support loopback.

A player is refused because of mods

Cause: their mod list or RimWorld Together version differs from the server's.

Fix: match the versions and the mod list. See How to Set Up Mods on Your RimWorld Together Server.

Your changes to ServerConfig.json disappear (PlayNHost)

Cause: IP, Port and MaxPlayers are written by the panel at every start.

Fix: leave those three keys alone. The port is the one on Ports & Network and the player limit comes from your plan. Every other key in the file keeps your edits.

FAQ

Can I host a RimWorld Together server for free?

Yes. The server is a free download from the project's GitHub releases. You still pay for the machine and internet, and it must stay on while people play.

Which port does RimWorld Together use?

TCP 25555 by default. You can change Port in ServerConfig.json when you self-host.

How many players can join?

MaxPlayers in ServerConfig.json sets the limit (100 by default). Our plans are 20, 45 and 100 players.

Do I need a Steam account to run the server?

No. Players need RimWorld and the Workshop mod.

Can players join with different mods?

Not by default. The server refuses players whose mod list does not match, unless mod bypass is on. On PlayNHost that is Let players join with any mods.

How to host a RimWorld Together server (2026)