To install mods on a dedicated Project Zomboid server, stop the server, open the active profile in Zomboid/Server/, and add each mod’s numeric Steam Workshop item ID to WorkshopItems= and its exact internal Mod ID to Mods=. Save the file, restart the server, and have every player use the same game build, mod set, and load order. A Workshop ID tells the server what content to download; a Mod ID tells Project Zomboid what to activate. Supplying only one can leave a mod downloaded but disabled or produce a missing-mod error.
The procedure differs from enabling mods in the in-game Mod Manager. A dedicated server uses its own profile file, so changing a client’s subscribed or enabled list does not configure the server. Back up the active Zomboid folder before changing mods on an established world.
What do I need before installing Project Zomboid server mods?
Prepare the server profile, compatible Workshop content, both identifiers for every mod, and a backup before editing anything. Most installation failures come from changing the wrong profile, mixing game builds, or entering a Workshop ID where a Mod ID belongs.
- An active dedicated-server profile: Dedicated-server settings are stored under
Zomboid/Server/. You must identify the INI file for the server name you actually launch. - A compatible game build: Check that each Workshop item supports the server’s current Project Zomboid build. A client and server on different builds, or stale Workshop content, can prevent a connection.
- Both IDs for each mod: The numeric item ID in the Steam Workshop URL goes in
WorkshopItems=. The mod’s exact internal ID, normally shown in its mod information ormod.info, goes inMods=. - Author instructions: Read the Workshop author’s dependency and load-order requirements, especially for maps and mods that depend on other mods.
- A world backup: Copy the active
Zomboidfolder before adding or removing mods from an established save.
Do not begin by editing a client’s Mod Manager list. That list controls ordinary play on that computer; it does not replace the dedicated server’s two INI settings.
How do I install mods on a dedicated Project Zomboid server?
Use this sequence for each mod. The order matters because the server must download the Workshop item before the game can activate its internal ID, and the server must be restarted after the profile changes.
1. Stop the server and identify the active profile
Shut down the dedicated server cleanly before editing its files. Open the Zomboid/Server/ directory and locate the INI file matching the server profile or server name used by your launch process.
Editing a different INI file is a common reason for changes to appear to do nothing. If several profiles are present, compare the name you launch with the profile name in the file rather than assuming the newest or most recently edited file is active. Keep the server stopped until all changes are saved.
2. Confirm build compatibility for every mod
On each Steam Workshop page, check that the item supports the Project Zomboid build running on the server. The same check applies to the clients: a player on a different game build may be rejected or experience desynchronization even when the IDs are correct.
Do not treat a successful download as proof of compatibility. Workshop content can be present on disk while its scripts, maps, or dependencies are incompatible with the current build. If an author specifies a required companion mod or a particular order, record those requirements before editing the profile.
3. Copy the Workshop ID and Mod ID separately
Open the Workshop page for each item and record the numeric item ID shown in its URL. That number identifies the content Steam should obtain and belongs in WorkshopItems=.
Then find the mod’s internal identifier in the Workshop item’s information or its mod.info metadata. Copy the identifier exactly, including spelling and capitalization, for Mods=. The two values often look different: one is numeric and the other is the name the game uses internally.
For a mod that contains multiple modules, follow the author’s instructions for which internal IDs must be enabled. Do not invent an internal ID from the Workshop title; use the metadata supplied with the mod.
4. Edit the two INI lines
In the active profile, find the existing WorkshopItems= and Mods= entries. Put the numeric Workshop IDs in the first line and the exact internal IDs in the second line.
Preserve the list syntax already used by the profile and add items in the author’s required load order. Do not swap the fields, put a Workshop number in Mods=, or place an internal ID in WorkshopItems=. If the profile already contains working mods, retain them while adding the new entries.
Maps and dependency-heavy mods may require a specific order or a group of related entries. Follow the author’s instructions rather than alphabetizing the list. A syntactically valid line can still fail if a dependency loads after the mod that needs it.
5. Save the profile and restart
Save the INI file, then start the same server profile you identified in step one. During startup, the server downloads or refreshes the listed Workshop content and attempts to activate the internal IDs.
If startup fails, read the first fatal console or log line before changing unrelated settings. The earliest fatal message usually identifies the missing, incompatible, or incorrectly named entry that caused later errors. Stop the server again before making a corrective edit.
6. Verify from a client
Connect with a client running the same Project Zomboid build and the same mod set and order. Confirm that the client receives the expected Workshop content and that the connection completes without a missing-mod or synchronization error.
Have every regular player make the same build and mod-set check. A server can be configured correctly while one player is still using an older build, a stale Workshop copy, or a different order. Keep the backup made before step one until the world has been tested successfully.
What is the difference between a Workshop ID and a Mod ID?
They are different identifiers for different stages of loading. The Workshop ID points to downloadable Steam content; the Mod ID points to the internal package that Project Zomboid enables.
| Setting | Identifier to enter | What it does | Where to obtain it | Typical failure when wrong or missing |
|---|---|---|---|---|
WorkshopItems= |
Numeric Workshop item ID | Tells the server which Steam Workshop content to download or refresh | The number in the item’s Steam Workshop URL | Content is not obtained, or the server lacks the files it needs |
Mods= |
Exact internal Mod ID | Tells Project Zomboid which downloaded package to activate | Mod information or the package’s mod.info metadata |
Content downloads but remains inactive, or the client reports a missing mod |
A complete entry normally requires both values. Listing only the Workshop item can produce the most confusing symptom: the files appear to download, yet the mod does not affect the game. Listing only the internal ID asks the game to activate content the server may not have obtained.
Why did the server download a mod but not enable it?
The usual cause is that the Workshop ID is present but the exact internal Mod ID is absent or misspelled in Mods=. Check the metadata rather than copying the Workshop title, and match spelling and case exactly.
Check the internal ID
Stop the server and compare the value in Mods= with the identifier shown in the mod information or mod.info. Remove accidental spaces or altered characters only if they do not belong to the profile’s established list syntax. A title can contain punctuation or branding that does not appear in the internal ID.
Check that you edited the profile being launched
If the line is correct but behavior is unchanged, verify the profile path again. The active file is the one under Zomboid/Server/ associated with the server name you launch. Restart after saving; an edited but inactive profile cannot change the running server.
Check dependencies and order
A mod may download correctly and still fail to activate when a required companion is missing or appears in the wrong order. Add the related Workshop and internal IDs together, following the author’s stated dependency sequence. Test the combination in a backup or disposable world before applying it to an established campaign.
Read the first fatal message
When startup reports several errors, begin with the first fatal console or log line. Correct that specific missing, incompatible, or incorrectly named entry, restart, and then reassess any later messages. Changing unrelated server settings can obscure the original fault.
How do I keep clients from being rejected or desynchronized?
Every player must use the same game build, Workshop content, internal Mod IDs, and order as the server. A mismatch in any one of those areas can block a connection or cause desynchronization.
- Confirm the server’s current Project Zomboid build before choosing Workshop items.
- Give players the same mod list and the same order, including dependencies and maps.
- Have players refresh stale Workshop content when the server has updated a mod or when a build change has occurred.
- Compare the numeric Workshop IDs separately from the internal IDs; matching one list does not prove that the other list matches.
- Test with one client after each significant change rather than adding many unrelated mods at once.
If one player connects while another is rejected, compare that player’s build and mod state with the known-good client before changing the server profile. The server’s list is authoritative for the session, but clients still need compatible content.
How should I install map and dependency mods?
Install a map or dependency group as a single planned change. Identify every required Workshop item and internal Mod ID, then preserve the load order specified by the author.
Build the dependency set
Read the mod’s documentation for required libraries, map components, or companion packages. Record the numeric ID for each Workshop item and the exact internal ID for each package. Add all required entries rather than testing the main item alone.
Respect the required order
Keep dependencies ahead of the mods that rely on them when the author specifies an order. Do not sort the list alphabetically or move an existing map entry merely to make the list look tidy.
Test before using an established save
Restart the server with the complete set and connect from a client using the same build and order. Test in a disposable world or a verified backup first, because a map or dependency change can expose problems that are difficult to undo in a long-running world.
Can I add or remove mods without risking my existing world?
Back up the active Zomboid folder before changing an established save, and use a fresh or disposable world when the mod’s documentation requires it. Some additions may not affect an existing world retroactively, while removals or failed initialization can leave the save behaving unexpectedly.
Keep the pre-change backup until you have connected, loaded the relevant areas, and confirmed that the world behaves normally. If the save becomes unstable, stop testing on the original copy and restore the backup or move to a fresh world as the mod’s documentation directs.
Which installation route should I use: host, dedicated server, or managed hosting?
The right route depends on whether the server must remain available when the host player leaves and how much administration you want to perform. The mod identifiers and compatibility checks still matter, but the place you enter them changes.
| Route | How mods are configured | Main advantage | Main trade-off |
|---|---|---|---|
| In-game host or listen server | Use the game’s in-game Mod Manager and host controls | Easiest UI workflow for a small session | The host machine must remain running for the session |
| Dedicated server | Edit the active profile under Zomboid/Server/, using WorkshopItems= and Mods= |
Persists independently of a player client | Requires profile, file, restart, backup, and troubleshooting administration |
| Managed hosting | Use the provider’s control panel or support process for the server profile | Installation, updates, backups, and restarts may be delegated | Control, build support, mod tools, backup policy, and price vary by provider |
For a short cooperative session, hosting through the game can be sufficient. Choose a dedicated server when the world should continue independently of one player’s client. If you use managed hosting, confirm its current Project Zomboid build support, how it handles Workshop and Mod ID fields, whether you can control load order, how backups are restored, and what restart or update controls are available.
What should I check after every mod change?
Use this compact checklist whenever you add, remove, or update a mod:
- Stop the server cleanly.
- Confirm the INI file belongs to the server profile you actually launch.
- Back up the active
Zomboidfolder, especially when an established world is involved. - Verify that each Workshop item supports the server’s current build.
- Copy the numeric Workshop ID to
WorkshopItems=. - Copy the exact internal Mod ID from the mod metadata to
Mods=. - Keep the author’s dependency and load-order requirements intact.
- Save the file and restart the server.
- Read the first fatal console or log line if startup fails.
- Connect with a client using the same build, mod set, and order.
- Keep the backup until the world has been tested successfully.
This process separates downloading, activation, compatibility, and save safety into checks you can verify independently. It also gives you a known point to return to when a new Workshop update introduces a problem.
Frequently Asked Questions
Can I configure a dedicated server only from the in-game Mod Manager?
No. The in-game Mod Manager controls ordinary play on that client. A dedicated server reads its own profile under Zomboid/Server/, including the separate WorkshopItems= and Mods= entries.
What is the safest way to test a large mod collection?
Make a backup first, add the complete dependency set in the required order, and start with a disposable world. Connect with one matching client before inviting everyone or continuing on the established save.
Why do two players get different results from the same server?
Compare their game builds, Workshop content, internal Mod IDs, and ordering. One player may have stale Workshop files or a different list even when the server profile itself is correct.
What should I do when a mod update breaks the world?
Stop using the affected save, preserve the current files for diagnosis, and restore the backup made before the change. If the mod documentation calls for a fresh world, create one rather than forcing the updated content into the old save.