How to build a Linux dedicated server from Unity

The short answer

Unity builds a dedicated server as a sub-target of the desktop platforms. In Unity 6 you add a Linux Server build profile, switch to it and press Build. Unity strips audio, textures, meshes, shaders and rendering code that a headless server does not need, which cuts size, memory and CPU use. The output is a Linux x86-64 executable with a data folder.

Before you build

• Install the module. If the Linux Server platform is missing from the Platform Browser, choose Install with Unity Hub and add the Linux Dedicated Server module for your editor version.
• Separate server code from client code. Dedicated Server builds define the UNITY_SERVER scripting symbol, so you can write #if UNITY_SERVER to start networking and skip UI, audio and input.
• Use a fixed port and bind all interfaces. A server bound to 127.0.0.1 is invisible to the world.
• Plan for logs and exit codes. A server that quits silently is hard to diagnose. Log startup errors to standard output.

Build steps

1. Open Build ProfilesIn the Unity Editor choose File > Build Profiles.
2. Add the Linux Server platformSelect Add Build Profile to open the Platform Browser and choose Linux Server. If it is not listed, select Install with Unity Hub and add the module for your editor version.
3. Switch to the profileSelect Switch Profile so the new profile becomes active. A Dedicated Server build is a headless executable with no graphical interface.
4. Set server behavior in codeUse #if UNITY_SERVER to start your networking in server mode, bind to 0.0.0.0 and a fixed port, and skip UI, audio and input setup.
5. BuildSelect Build and choose an empty output folder. Keep the whole folder, since the executable needs its data directory.
6. Test on Linux and packRun it headless on Linux, join from another machine, set the executable bit, then archive the folder with tar -czf server.tar.gz . with no symbolic links or secrets inside.

Test the build the way a host will run it

On a Linux x86-64 machine or container, extract the archive and run the server with the same arguments you will declare:

mkdir game && tar -xzf server.tar.gz -C game
chmod +x game/UnityServer.x86_64
./game/UnityServer.x86_64 -batchmode -nographics

In a second terminal check that the port is open (ss -lunp for UDP, ss -ltnp for TCP) and join with a client from another machine. If the server exits immediately, read its log; exit code 127 usually means a missing library or the wrong architecture, and 139 a crash inside the program.

Common mistakes

Next

Pick the networking page that matches you: Unity Mirror or Unity NGO, then use the ports and firewall checklist. If your server uses neither and speaks its own TCP or UDP protocol, read the custom native section of the manifest guide: a direct, limited lane where you supply the join probe.

Frequently asked questions

Written by Charging Bull Software. Facts on this page are checked against the product source and dated sources listed above; where something is not proven, the page says so.