Host a Project Zomboid dedicated server on your PC

This is for someone who has never run a game server. You will put the free Project Zomboid dedicated server on a Windows PC so friends can play even when you are not in the world. The PC has to stay on while people play.

1. Install the dedicated server

1. Open Steam.
2. At the top of your Library, open the dropdown that says Games. Tick Tools.
3. Find Project Zomboid Dedicated Server. Click Install. This is not the game you play.

2. Set a join password

1. In Steam, hit Play on Project Zomboid Dedicated Server once, then close it. That creates the settings files.
2. Open File Explorer and go to C:\Users\<you>\Zomboid\Server\. Replace <you> with your Windows username. The ini is named after the server (often something like servertest.ini).
3. Open that ini in Notepad and set a join password, for example:

Password=yourfriendssecret
PublicName=Friends
MaxPlayers=4
UPnP=false
BackupsOnStart=false

Save the file. Friends will type that password when they join.

3. Forward two ports

On your router, forward UDP 16261 and 16262 to this PC. Friends join with your public IP (or hostname) plus the password from step 2. Need a click-by-click router walkthrough? See Port forwarding.

4. Start the server

1. In Steam, hit Play on Project Zomboid Dedicated Server.
2. Wait until it finishes loading. Leave that window open while people play.

5. Join

In the Project Zomboid game, join by IP or hostname. Type the join password if you set one.

If the PC runs out of memory or the server vanishes

The stock server asks Java for a lot of RAM. Only do this if the server keeps dying or the PC runs out of memory.

1. In Steam, right-click Project Zomboid Dedicated Server → Manage → Browse local files.
2. Open ProjectZomboid64.json in Notepad.
3. Change the heap lines so you only keep a 2 GB cap with G1. For example:

Before: something like -Xmx8g / -Xms8g

After: -Xmx2g and -XX:+UseG1GC (and remove the leftover 8 GB lines).

Save the file, then start the server again from Steam.

That’s enough for a small co-op world at home. If you’d rather skip port forwards and leaving a PC awake, omnipass.gg can run it for you.