# Project Zomboid server hosting for Build 42 and Build 41 > Host a Project Zomboid server for Build 42 multiplayer or Build 41, with Workshop mods and maps, your own sandbox rules and RAM sized for your group. Survival · Sandbox Survive Knox County together on a server that keeps running when you log off. Run Build 42 with its new multiplayer or stay on Build 41, add Workshop mods and maps, and set the sandbox rules for your group. - Build 42 multiplayer, or Build 41 on the legacy branch - Workshop mods and maps, downloaded when players join - Sandbox settings for zombies, loot and time - Memory sized by player count See plans Find your size Version Build 42 multiplayer reached the stable branch with 42.20 on 29 July 2026. Build 41 stays on the legacy41 beta branch; saves do not carry over. Build 42 · Build 41 on legacy41\ Players Set MaxPlayers in servertest.ini; admins do not count. Hotfix 42.20.3 raised the supported limit to 254 players. 32 by default (MaxPlayers)\ Ports 16261/UDP is the default port for Steam queries, 16262/UDP for direct connections. 16261–16262 UDP\ RAM The Project Zomboid wiki suggests about 3 GB plus around 500 MB per player, so 4 players need about 5 GB. About 3 GB + 0.5 GB per player\ Mods Steam Workshop, downloaded on join\ Settings servertest.ini · SandboxVars.lua Server styles - Build 42 - Build 41 - Vanilla - Modded - PvE - PvP - Roleplay Game facts from the Project Zomboid wiki and The Indie Stone’s Steam announcements, checked in October 2026. - DDoS protection - 20 game server locations ## Project Zomboid plans are being prepared Tell us your build, player count and mods, and our team will reply with the options. Or open a ticket and we will let you know when the plans are online. [Contact sales](https://hyperdc.com/contact-us) [Open a ticket](https://hyperdc.com/support/new-ticket) ## How much RAM does a Project Zomboid server need? The wiki rule of thumb is about 3 GB plus around 500 MB per player. Mods and map mods add more. | Feature | **Small group** Up to 4 players | Recommended **Community** Up to 16 players | **Large** Up to 32 players | **Very large** 32+ players | | --- | --- | --- | --- | --- | | Memory (RAM)Working memory for the world, the players and every mod. Leave headroom: memory use grows as players explore. | 6 GB | 12 GB | 20 GB | 24 GB+ | | CPU coresThe game simulates the world mostly on one thread, so fast cores matter more than many cores. | 2–4 | 4 | 4–6 | 6+ | | Disk spaceRoom for the game files, the world and its backups, plus updates and mods. | 15 GB | 20 GB | 30 GB | 40 GB | | Typical use | A few friends in Knox County | A community server with mods | A busy public server | Large roleplay or event servers | - ### Small group Up to 4 players Memory (RAM)Working memory for the world, the players and every mod. Leave headroom: memory use grows as players explore. 6 GB\ CPU coresThe game simulates the world mostly on one thread, so fast cores matter more than many cores. 2–4\ Disk spaceRoom for the game files, the world and its backups, plus updates and mods. 15 GB\ Typical use A few friends in Knox County - Recommended ### Community Up to 16 players Memory (RAM)Working memory for the world, the players and every mod. Leave headroom: memory use grows as players explore. 12 GB\ CPU coresThe game simulates the world mostly on one thread, so fast cores matter more than many cores. 4\ Disk spaceRoom for the game files, the world and its backups, plus updates and mods. 20 GB\ Typical use A community server with mods - ### Large Up to 32 players Memory (RAM)Working memory for the world, the players and every mod. Leave headroom: memory use grows as players explore. 20 GB\ CPU coresThe game simulates the world mostly on one thread, so fast cores matter more than many cores. 4–6\ Disk spaceRoom for the game files, the world and its backups, plus updates and mods. 30 GB\ Typical use A busy public server - ### Very large 32+ players Memory (RAM)Working memory for the world, the players and every mod. Leave headroom: memory use grows as players explore. 24 GB+\ CPU coresThe game simulates the world mostly on one thread, so fast cores matter more than many cores. 6+\ Disk spaceRoom for the game files, the world and its backups, plus updates and mods. 40 GB\ Typical use Large roleplay or event servers Sizes follow the wiki rule of about 3 GB plus around 500 MB per player, with headroom. The server only uses the Java memory set with -Xmx, so raise it together with the plan. ## Builds, sandbox and mods Pick the build, then set the rules of your apocalypse. ### Build 42 or Build 41 Build 42 brings the new multiplayer to the stable branch; Build 41 stays available on legacy41. Saves do not move between builds. ### Sandbox settings Zombie count and speed, loot, time and the start date are set in the server’s SandboxVars.lua. ### Workshop mods Add the mod ID to Mods= and the Workshop number to WorkshopItems=; players download missing mods when they join. ### Map mods Custom maps also need an entry in Map=, listed ahead of the base map. ### Access levels Give players roles with /setaccesslevel: observer, gm, moderator or admin. ### Java memory The server uses the memory set with -Xmx in StartServer64.bat or ProjectZomboid64.json; keep it below the plan’s RAM. ## Set up your Project Zomboid server Four steps to your first night in Knox County. 1. ### Pick build and size Build 42 or Build 41, then the memory for your group from the table above. 2. ### Pick a location Choose the one closest to your group from our 20 game server locations. 3. ### Set up servertest.ini Set the server name, password and MaxPlayers, add mods to Mods= and WorkshopItems=, and tune the sandbox settings. 4. ### Join the server Choose Join, add the address and port 16261 to Favorites with your account name and password, and connect. ## Other game servers you might like [See every game](https://hyperdc.com/game-server-hosting) ### 7 Days to Die Horde nights with random worlds, modlets and crossplay. [Learn more](https://hyperdc.com/game-servers/7-days-to-die) ### DayZ PC servers on Chernarus, Livonia or Sakhal with your own loot and mods. [Learn more](https://hyperdc.com/game-servers/day-z) ### Valheim Up to 10 Vikings with crossplay, modifiers and backups. [Learn more](https://hyperdc.com/game-servers/valheim) ### Terraria Vanilla or tModLoader worlds for up to 255 players. [Learn more](https://hyperdc.com/game-servers/terraria) ### Minecraft Java and Bedrock worlds with plugins, modpacks or crossplay. [Learn more](https://hyperdc.com/game-servers/minecraft) ### The Forest Co-op survival for eight players with your own difficulty and modes. [Learn more](https://hyperdc.com/game-servers/the-forest) ## Frequently asked questions Still have a question? Send us a message and our team will reply by email. [Contact us](https://hyperdc.com/contact-us) [Open a ticket](https://hyperdc.com/support/new-ticket) ### Does Build 42 have multiplayer? Yes. Build 42 multiplayer reached the stable branch with version 42.20 on 29 July 2026, and 42.21 followed in September. Build 41 is still available on the legacy41 beta branch. ### Can I keep my Build 41 world? Not in Build 42: Build 41 saves do not open in Build 42. Keep the server on the legacy41 branch to continue an old world. ### How many players can join? MaxPlayers in servertest.ini is 32 by default, and admins do not count. Hotfix 42.20.3 raised the supported limit to 254 players. ### How much RAM does a Project Zomboid server need? The Project Zomboid wiki suggests about 3 GB plus around 500 MB per player, so 4 players need about 5 GB. Mods and map mods need more, and the server only uses what -Xmx allows. ### Which ports does the server use? 16261/UDP is the default port and handles Steam queries; 16262/UDP takes direct connections. Both have to be reachable. ### How do I add mods? Put each mod ID in Mods= and each Workshop number in WorkshopItems= in servertest.ini; map mods also need Map=. Players download missing mods when they join, and some mods ask players to restart the game. ### Why do players get a version mismatch? Client and server must run the same build. Stop the server and update it after a game update; it does not update while it runs. ### How do players join? Choose Join, open Favorites and enter the address, port 16261 and an account name and password, then save and connect. Public servers are also in the Internet list. ### How do I reset the world? Stop the server and delete its world folder, named after the server (servertest by default). Players stuck on Loading the World can delete their local copy of the server save. ### How do I make someone an admin? Use /setaccesslevel with the user name and a level such as admin, moderator, gm or observer, from the server console or in the chat. ## Ready to survive Knox County together? Tell us your build, players and mods, and we will help you pick the right Project Zomboid server. See plans [Contact sales](https://hyperdc.com/contact-us) --- Source: \ Updated: 2026-10-08