How to Install Mods on Your Arma 3 Server

Sep 14, 2026 3 min read

Arma 3 mods come from the Steam Workshop, but getting them onto your server here is a manual process: you'll download each mod through the Arma 3 Launcher on your own PC first, then upload the files to your server yourself. This guide walks through the whole process, start to finish.

💡 Note: Make sure you include any dependencies your mods require, like Community Base Addons (CBA_A3) for most major mods, or they may fail to load.

Step 1: Download Your Mods

Open Arma 3 to launch the Arma 3 Launcher.
Go to the MODS tab and subscribe to each mod you want on the Steam Workshop.
Let Steam finish downloading them.

Step 2: Find And Rename Your Mod Folders

Steam stores each downloaded mod under steamapps\workshop\content\107410\ on your PC.
Rename each mod's folder to add an @ in front of its Workshop ID, for example 450814997 becomes @450814997.

Step 3: Upload To Your Server

Upload each renamed @ folder to your server's root directory.
Inside each mod folder is a keys (or Keys) folder containing a .bikey file. Copy every one of these into your server's own keys folder, so players using the mod aren't rejected by the signature check.

💡 Pro Tip: Some mods, like RHS or CUP, run several gigabytes each. For anything beyond a mod or two, upload over SFTP Details with an app like FileZilla or WinSCP instead of the browser Files tab, it handles large folders far more reliably.

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Step 4: Tell Your Server Which Mods To Load

Once your mod folders and keys are uploaded, head to the Game Settings tab and point your server at them. Either field below works, since both just build your server's mod list from folders that are already on your server, they don't fetch anything themselves.

Additional Mods: list your uploaded folder names separated by semicolons, for example @450814997;@463939057;
Modlist File (Exported From A3 Launcher): upload an HTML modlist exported from the Arma 3 Launcher's Mods tab, then type its filename here (commonly modlist.html). The server reads the mod list from this file instead of the Additional Mods field.

⚠️ Neither Field Downloads Mods For You: Whichever you use, the mod folder still has to already be uploaded per Step 3. If a mod is listed here but its folder isn't on the server, your server will simply start without it, with no error. If a mod isn't working, double-check its folder actually exists in the Files tab first.

Folder names in the Additional Mods field can't use capital letters, spaces, or start with a number, so keep the leading @ and numeric Workshop ID format from Step 2.

💡 Note: If a mod isn't loading after an upload from a Windows PC, casing is a common culprit. Turn on [Repair] Make Mod Files Lowercase on the Game Settings tab for one restart to fix it automatically, then turn it back off.

Restart your server once your mods are uploaded and listed, and you're ready to play. If you run into any trouble getting mods installed, no worries! Just open a support ticket and our team will gladly jump in and help.

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