Project Zomboid plans differ mainly by RAM, because Build 42 is a memory-hungry game — the server simulates animals, deep buildings and a persistent world whether or not anyone is watching, and it's a Java application that needs heap headroom to run smoothly. Here's how to pick, and how to change your mind later without losing anything.
The honest baseline
Build 42 uses roughly 6GB before a single mod loads. That's why our plans start at 10GB — in our own testing an 8GB server was killed by the system while generating its first world, so a smaller plan would be selling you the support ticket.
Which plan fits your group
| Plan | RAM | Fits |
|---|---|---|
| Survivor | 10GB | Vanilla or lightly-modded groups up to ~10 players |
| 12GB | 12GB | The sweet spot: real mod lists, 10–20 players, long-running worlds |
| 16GB | 16GB | Heavy mod lists, 20+ players, big community servers |
Two things move you up a tier faster than player count:
- Mods. Item packs, map expansions and overhaul mods each add world state the server tracks continuously. A 50-mod list belongs on 12GB minimum.
- World age. Zomboid persists everything your group does — months-old worlds simply weigh more than fresh ones.
Player count matters less than people expect: the world simulation is the fixed cost, and each player adds roughly half a GB of working headroom on top.
What every plan includes
All plans run the same everything-else: your choice of region, full config and file access, the mods system, scheduled restarts, dashboard backups (slot count grows with tier), and the same network. You are never paying for "premium support" or per-player seats — RAM and backup slots are the real differences.
The heap detail (so the numbers make sense)
A Java server can't use every byte of its machine — the game's memory ceiling (the JVM heap) is set to about 75% of your plan's RAM, with the rest reserved for the runtime and OS. That's tuned for you automatically; it's why a "10GB plan" behaves like the ~7GB-heap server the community sizing guides describe. If you've self-hosted before: yes, that's the -Xmx flag, already handled.
Upgrading (and what happens to your world)
Upgrade any time from your service's page — your world, mods and settings come with you; an upgrade changes the resources under the server, not the server itself. The swap happens on a restart, so time it for a quiet moment. Downgrades work the same way, with one honest warning: a world that grew into 16GB won't enjoy going back to 10GB.
Signs you've outgrown your tier
- Rhythmic whole-server freezes (everyone at once, every minute or so) that get worse the longer the server runs and reset after a restart — that's memory pressure, the classic outgrown-plan symptom.
- Restarts after mod additions take much longer and the console shows memory warnings.
If you're seeing that on 12GB with a modest setup, open a ticket before upgrading — occasionally it's one broken mod, not the plan, and we'd rather find that than take the upgrade.