Project Zomboid Save Files and Backups
Where Knox County actually lives on disk, how to copy it, and which Steam branch matches which world.
After every hotfix someone searches “Project Zomboid save location” because Steam updated, a mod failed to load, and the main menu forgot last week’s town. The game does not keep your worlds inside the Steam install folder. They live in the Zomboid cache. Build 42.20.4 (26 August 2026) is save-safe for 42.20.x worlds according to official notes—but only if you are on the matching branch and you do not load a Workshop list that injects removed Lua. This page is the folder map. Branch lore stays on 42.20.4 Hotfix and Returning Players.
Where the files are
Windows: %UserProfile%\Zomboid
Paste that into Explorer. You should see at least:
- Saves — solo and hosted worlds, split by mode folders (Sandbox, Apocalypse, Multiplayer, and similar labels your client uses).
- Logs — crash and load errors. Zip these before you post on forums.
- Lua / mods leftovers — local overrides. Workshop content still lives under Steam’s workshop directory; do not confuse the two.
- Server — dedicated INI,
WorkshopItems,Mods, and server saves if you host from this PC. See Dedicated Servers.
Linux: commonly ~/.local/share/Zomboid (same subfolders).
macOS: under your user Library Application Support path for Zomboid—same cache idea, not the .app bundle.
Uninstalling the Steam game does not delete this cache. That is why a “fresh install” still has last year’s broken save. Deleting Zomboid does wipe settings and worlds. Copy first.
How to back up without drama
- Quit the game completely. Do not copy a world that is mid-write.
- Copy the entire Saves folder to a dated directory (
Zomboid-Saves-2026-08-28). - If you host, copy Server too.
- Screenshot Mod Manager load order. Folders do not record drag-and-drop sequence by themselves in a way you will remember at 2 a.m.
Restore by quitting, replacing the folder, and launching. If a mod added items and you restored a backup from before that mod, either re-enable the mod or accept missing objects. Loading once with a bad mod can dirty map cells—hence the copy before experiments. Mods covers that failure mode.
Steam branches versus folders
Steam betas change the executable. They do not magically convert a Build 41 folder into Build 42.
| Save origin | Load it on |
|---|---|
| Build 41 | legacy41 (41.78.21 as of 26 Aug 2026) |
| Build 42.19 worlds | 42.19 beta (42.19.2 same day) |
| Build 42.20.x | Default None / Stable 42.20.4 |
Do not copy files between these trees and hope. Build 42 Overview is explicit: 41 ≠ 42, 42.19 ≠ 42.20. 42.20.4 should accept 42.20.3 worlds.
Cloud sync is not a backup strategy for Knox County. It can fight you during branch switches. Local copies win.
After the 42.20.4 security hotfix
If the client crashes on enable mods, your save may still be fine. Disable Workshop items, load vanilla, confirm the town is there, then add mods back one author at a time. loadstring / loadstream removals break specific Lua, not the map format. Details: 42.20.4 Hotfix.
If you cannot load even vanilla, restore yesterday’s copy. Do not run random “save repair” Workshop tools on a unique 400-hour world without a second copy.
Multiplayer worlds
Host backups are the server’s save directory, not each client’s Screenshots folder. Clients keep characters inside the server world. If the host rolls back, everyone rolls back. Agree on that before patch night. Servers and Co-op is the etiquette page.
Related habits that save seasons
- Name worlds with the build string (
Rosewood-42204). - After 42.20.4, pin the menu string in Discord.
- Keep a USB or second drive copy of Saves, not only another folder on the same dying HDD.
- Logs plus a backup beat a 2,000-word forum post with no files.
The county is one folder. Treat it like the generator keys.
Frequently Asked Questions
Quick answers to the most common questions.
Where is the Project Zomboid save folder on Windows?
%UserProfile%\Zomboid\Saves. The Steam install directory is not where worlds live. Copy Saves (and Server if you host) while the game is closed.
Will Build 42.20.4 delete my 42.20.3 save?
Official notes say 42.20.x saves should remain compatible. Still copy the folder first. 42.19 and Build 41 worlds stay on their own Steam branches.
Does reinstalling the game delete saves?
Usually no. Saves live in the Zomboid cache outside the install. Deleting the Zomboid folder does wipe them. Backup before you “clean install.”
My save vanished after a mod update. What now?
Quit, restore the last Saves copy, load vanilla, then re-enable mods carefully. See Mods and 42.20.4 Hotfix if Lua errors mention loadstring.
Can I move a Build 41 save into Build 42?
No. Keep Build 41 on legacy41. Start a new 42.20.4 world for the glow-up map. Returning Players covers the habit reset.