Project Zomboid Server Hosting

Why use a rented server for Project Zomboid?

A rented Project Zomboid server keeps the world online without depending on the host being in the game, and lets every player connect on their own schedule and keep surviving. In the in-game hosting mode, the server runs alongside the game on the host's computer; when the host leaves, the world stops and the other players wait.

Project Zomboid is a simulation that tracks every house and item in Knox County along with thousands of zombies. As players spread out to different parts of the map, the server loads each player's surroundings separately, pushing memory and CPU load to a level a home computer cannot easily carry. In long-running worlds, the bases players build and the items they store enlarge the save data.

A dedicated server stays online 24/7 in a data center; dedicated memory and CPU keep the server smooth even with large zombie hordes. NVMe storage makes a clear difference in reading and writing the thousands of small map chunk files quickly. Players connecting from Türkiye and the surrounding region benefit from a short route to a server located in Türkiye; in Project Zomboid, where melee combat is decisive, this means hits register more consistently.

How much RAM does a Project Zomboid server need?

The Project Zomboid server is Java-based, and the amount of memory it can use is capped by the -Xmx value in the launch settings; the server's total memory must be larger than this value, with the difference left for the operating system and Java's own overhead. The table values are estimated ranges showing the server's total memory.

Keep these points in mind when planning memory:

• Set -Xmx correctly: the default memory setting is written for small groups. For example, on an 8 GB server, a value such as -Xmx6g leaves room for the operating system. Setting -Xmx equal to total memory can cause the operating system to kill the server.
• Player spread: each player loads the map chunks around them. When players scatter to different towns, memory usage rises.
• Zombie population: zombie density and horde behaviour in the sandbox settings affect both memory and CPU.
• Mods: mods that add new vehicles, map extensions and items noticeably increase memory needs; map mods are especially heavy.

When memory runs short, Java's garbage collection runs more often and players experience brief freezes; at a later stage, the server shuts down with an out-of-memory error. On Linux, tools such as htop and free -h let you monitor memory usage.

Ready-made package or VDS for a Project Zomboid server?

A flexible and predictable infrastructure for a Project Zomboid server is a VDS with resources reserved for you; the package table on this page shows the current VDS options suitable for Project Zomboid live. On a VDS, you manage the Java memory setting, the mod list and the backup scheme entirely yourself.

You can open the server in two ways:

1. Your own installation: when ordering a VDS server, choose Ubuntu or Windows Server and run app_update 380870 with SteamCMD. On Linux the server starts with start-server.sh, and on Windows with StartServer64.bat. On first launch, the admin password is set and the config files are created.
2. Installation via support ticket: if you would rather not deal with the command line, you can open a ticket for a Project Zomboid installation from the Support section of the customer panel after ordering the VDS. Just specify the player limit, the Workshop mods you want and the game branch (Build).

On a VDS you can open a test world on the same server and try mod updates there first, which reduces the risk of corrupting the main world. You can find a comparison of the two routes on the game server package or VDS page.

Which ports does a Project Zomboid server use?

By default, a Project Zomboid server uses port 16261/UDP for the main connection and 16262/UDP for direct connection traffic; both ports must be open as UDP in the firewall for players to connect. The port values can be changed with the DefaultPort and UDPPort lines in the server config file.

If you use RCON, keep the RCONPassword value strong and open the RCON port only to your own IP address. If you run a second Project Zomboid world on the same server, give it a different -servername and different port values; two servers cannot share the same ports. Players connecting directly enter the IP address and the DefaultPort value on the in-game add-server screen.

If the server shows up in the list but players cannot connect, usually only the first port has been opened and the second was forgotten. On Linux, the ss -ulpn command shows which UDP ports the server is actually listening on, so you can compare your firewall rules against that output. After changing port values you need to restart the server.

Build 41 or Build 42: which version should you run a server on?

The first decision when opening a Project Zomboid server is which game branch (Build) to use, because the server and all players must be on the same branch and saves from different branches cannot be moved between them. Build 41 was the stable standard for multiplayer for a long time; Build 42 is a branch that brings new systems, with multiplayer support being developed in stages.

When deciding, look at the following:

• Stability: a branch marked as unstable receives frequent updates and save compatibility can break. For a long-running community world, prefer the current stable branch; check which branch is stable in the betas tab of the game's properties on Steam.
• Mod compatibility: mods are written for a specific branch. Many mods written for Build 41 do not work on the new branch or are awaiting updates. If your mod list is long, first check which branch the mods support.
• Server branch: in SteamCMD, the branch the server downloads is selected with the -beta parameter. Players' client branch must match the server.

Switching from one branch to another usually requires starting a new world. So announce the switch to your community in advance and keep a backup of the old world; you will need it if you ever want to return to the old branch.

How do you configure Project Zomboid server settings?

Project Zomboid server settings are kept in the Zomboid/Server directory in the user folder, in three files starting with your server name: servername.ini for general server settings, servername_SandboxVars.lua for the game world's rules, and servername_spawnregions.lua for the regions where players spawn. Since the default server name is servertest, the files often appear with names such as servertest.ini.

• servername.ini: PublicName, PublicDescription, Public, Password, MaxPlayers, PVP, PauseEmpty (pause time while the server is empty), Open (whitelist off/on), SaveWorldEveryMinutes, the mod lines and RCON settings.
• SandboxVars.lua: world rules such as zombie population and speed, infection type, loot abundance, when electricity and water shut off, seasons and vehicle frequency.
• spawnregions.lua: which towns players can start in (such as Muldraugh, West Point, Riverside and Rosewood).

Edit the settings while the server is stopped; changes made while it is running can be overwritten on shutdown. Some sandbox settings only take effect when a new world is created; for example, changing the day of the power shut-off after the world has started may not give the expected result. Many settings can also be changed from the in-game admin panel, but working through the files is safer for a persistent, traceable setup.

How do you add Workshop mods to a Project Zomboid server?

To add Steam Workshop mods to a Project Zomboid server, you fill in two lines in the server config file: the WorkshopItems= line with the numeric IDs from the Workshop page, and the Mods= line with the mod IDs inside the mod folders. For mods that add maps, the map folder name is also added to the Map= line. The server downloads the mods from the Workshop itself on startup, and missing mods are downloaded automatically when players connect.

1. Note the mod's numeric ID (Workshop ID) from the Workshop page and the mod ID (Mod ID) given in the description.
2. Add the Workshop IDs to the WorkshopItems= line and the mod IDs to the Mods= line, separated by semicolons.
3. For a map mod, write its map folder in the Map= line before the default map.
4. Restart the server and confirm in the log that the mods loaded.

A single Workshop item can contain more than one mod; you need to add each one's mod ID separately. When a mod updates and the server and player versions do not match, players cannot connect; in that case, restarting the server usually updates the mods. Adding a map mod to an existing world or removing a mod can cause inconsistencies in the world; take a backup before every mod change.

How can you improve Project Zomboid server performance?

The key to Project Zomboid server performance is a correct Java memory setting, a reasonable zombie population, a controlled mod list and regular restarts. Players usually notice performance problems as zombies teleporting, doors opening late, vehicles getting stuck or brief freezes.

• Memory setting: set -Xmx below the server's total memory, leaving room for the operating system. Too low a value causes frequent garbage collection freezes; too high a value leads the operating system to kill the process.
• Zombie population: do not overdo the population multiplier and peak population in SandboxVars on busy servers; every zombie requires pathfinding and behaviour calculations.
• PauseEmpty: pausing time while the server is empty prevents unnecessary load and the world progressing without players overnight.
• Save interval: keeping SaveWorldEveryMinutes too short causes pauses on large worlds.
• Scheduled restarts: on modded servers that stay up a long time, an announced daily restart clears memory build-up.

Because a Project Zomboid world save consists of thousands of small files, disk speed directly affects save and map loading times; NVMe storage noticeably eases this load.

How do you keep a Project Zomboid server secure?

The foundation of a secure Project Zomboid server is access control through a whitelist or password, careful distribution of admin rights, protecting RCON and network-level DDoS protection.

• Whitelist: with Open=false, only accounts created by an admin can connect. This is the safest method for closed communities; player accounts are added from the admin panel or with a command.
• Password: use the Password setting for a server that is visible in the public list but open only to your community.
• Admin access: the admin password is set on first launch; grant rights only to people you trust with the setaccesslevel command.
• Anti-cheat: keep the anti-cheat options in the server settings enabled and watch for suspicious player behaviour in the server logs.
• RCON: disable it if you do not use it; if you do, apply a strong password and IP restriction.

On LIONFIN infrastructure, the RouteFence firewall filters DDoS traffic at the network level before it reaches your server, supported by 24/7 NOC and SOC monitoring in our data center. On a VDS, keep the operating system up to date and use key-based SSH access.

How do you back up and migrate a Project Zomboid world?

A Project Zomboid server's world data is kept in the Zomboid/Saves/Multiplayer/servername directory in the user folder, while player accounts and the whitelist are kept in the Zomboid/db/servername.db file; settings are under Zomboid/Server. Backing up these three locations together is enough to restore the server completely.

1. Run the save command on the server, then shut it down cleanly with quit.
2. Archive the Saves/Multiplayer/servername folder, the db/servername.db file and the config files in the Server folder.
3. Install the same game branch and the same mod list on the new server.
4. Upload the files to the same paths and start the server with the same -servername value.

Since the world folder consists of thousands of small files, creating a compressed archive first is much faster than copying the files one by one during migration and backup. Build 41 and Build 42 saves cannot be moved between each other; before migrating, make sure both servers are on the same branch. Keep a copy of your backups off the server.

What are the most common Project Zomboid server errors?

The most common problems on Project Zomboid servers are mod version mismatches, a branch difference between server and client, Java memory errors and closed ports. The server console and the logs in the Zomboid/Logs folder are the first step of diagnosis.

For infrastructure issues, you can open a support ticket from the Support section of the customer panel; include the relevant lines from the server log so the problem can be identified quickly.

Which game rules should you choose on a Project Zomboid server?

What shapes a Project Zomboid community server most is the zombie type and population, infection rules, PvP status and when utilities shut off. These settings directly define the world's difficulty and how players relate to each other.

• Group of friends (PvE): slow zombies, a medium population and a somewhat later power and water shut-off are a balanced start for groups who want to build a base together and play for the long haul. Player-versus-player damage is disabled with PVP=false.
• Hardcore survival: a high population, fast zombies, scarce loot and an early utility shut-off raise the tension for experienced groups, but can be too harsh for new players.
• PvP and roleplay servers: once PvP is enabled, safe zones, player-killing rules and base raiding conditions must be written out clearly. Roleplay servers usually require extra mods and strict administration.

Write the rules in the PublicDescription field and in your community channels. Changing some sandbox settings after the world has been created may not apply to the existing world as expected; making the important decisions before opening the server saves you from an unnecessary reset later.