Short answer to the main question: yes, mods work on pirated copies of Oxygen Not Included. The mod installation mechanics are built into the game itself and do not depend on Steam: on startup the game scans the local mods folder and loads everything it finds there. GOG and Epic Games Store are the same story: these versions simply have no Steam Workshop, so local installation is the only fully working method. Below is how to do it properly on any copy of the game.
How the game finds mods
Oxygen Not Included loads mods from two sources. The first is the Steam Workshop: it is only available if the game was purchased and launched through Steam. The second is the local mods/Local folder in the Klei profile: it always works, on any version of the game. The game does not check the license when loading local mods, which is why for pirated, GOG and Epic copies the Local folder is the main route. The only requirement: the mod version must match the game version (more on that below).
Where to put mods: the Local folder
Local mods go into the same folder no matter which store the game was bought (or not bought) from. Full paths:
- Windows: C:\Users\your_username\Documents\Klei\OxygenNotIncluded\mods\Local (that is, %USERPROFILE%\Documents\Klei\OxygenNotIncluded\mods\Local)
- macOS: /Users/your_username/Library/Application Support/unity.Klei.Oxygen Not Included/mods/Local
- Linux: ~/.config/unity3d/Klei/Oxygen Not Included/mods/Local
The mods and Local folders may not exist on a fresh installation — just create them manually. Inside Local, each mod must have its own separate folder.
Installing a mod step by step
- 1Download the mod archive. For GitHub mods this is a zip file from the author's Releases page; for mods in our catalog — the "Download" button on the mod card.
- 2Unpack the archive into the Local folder. After unpacking you should get a structure like Local\ModName\mod_files: each mod keeps its manifest (mod.yaml or mod_info.json) and the mod library (.dll) inside its own folder.
- 3Launch the game and open the main menu → "Mods". Local mods appear in the list marked as manually installed.
- 4Tick the checkbox next to the mod and restart the game when it offers to. Done — the mod is active.
Let's walk through a live example — Fast Track, an optimization mod by Peter Han. Download FastTrack.zip from the GitHub releases page (or via the button on the mod card), unpack it into Local — you get a Local\FastTrack folder with FastTrack.dll, mod.yaml and mod_info.yaml inside. Launch the game, enable Fast Track in the "Mods" menu, restart — and the game starts running faster. Any other local mod installs exactly the same way.
vU59Fast Track
by Peter Han
Performance optimization mod by Peter Han: higher FPS, less lag on large colonies. Public beta 0.18.5.0; GitHub only.
Blueprints Expanded
by Sgt_Imalas
Blueprints Expanded An updated and improved Blueprint mod - now with settings transfer and material swapping. [img]https://raw.githubusercontent.com/Sgt-Imalas/Sgt_Imalas-Oni-Mods/refs/head
Where to get mods when Steam is unavailable
The authors' GitHub pages are the main source. Many well-known ONI mod authors publish ready-made builds in the Releases section of their repositories: Peter Han (ONIMods — Fast Track, Speed Control, PLib and dozens more), Sgt-Imalas (Blueprints Expanded and about a hundred mods), aki-art and others. On our site every mod card has a link to the source and a working file mirror — you can download directly. Another verified reference is the Modding page on wiki.gg with a general overview of the game's mod system.
Safety rule: a real ONI mod is an archive containing a folder with mod.yaml/mod_info.json and a .dll. Never run .exe "mod installers" from unverified sources.
Dependencies
You don't need to download any libraries or frameworks before installing mods: everything required is already built into the game itself, and mods use it automatically — unlike some other games where you have to install a separate library mod first. Just drop the mod folder into Local and enable it in the in-game Mods menu. If a mod's description lists other mods as required dependencies (rare), download them the same way and place their folders next to it in Local.
Game versions and compatibility
Every mod manifest (mod_info.yaml) has a minimumSupportedBuild parameter — the minimum game build the mod works on. If your build is older, the game will mark the mod as incompatible or refuse to enable it. The current game version at the time of writing is U59 (build 737790); mods released after the Bionic Booster Pack update and the QoL fixes are built for it. Practical takeaway: keep the game updated to the latest build — pirated builds labeled U59 or newer are compatible with current mod versions.
If something went wrong
- The mod does not appear in the list — almost always wrong nesting: Local\ModName\ must contain the mod folder with mod.yaml. If the archive unpacked as Local\ModName\ModName\mod.yaml, move the contents one level up.
- The game crashes on load — remove the mod folder from Local and the game starts as if nothing happened. The crash is usually caused by a game/mod version mismatch.
- A Steam version and a local copy of the same mod — never enable both at once: duplicate mods break loading. Disable the Steam version in the mods list.
- The mod is "enabled" but does not work — check that OneDrive is not redirecting the Documents folder: syncing can block mod file writes. Disable OneDrive for Documents or move the folder.
- Logs for finding the cause — the Player.log file in %USERPROFILE%\AppData\LocalLow\Klei\Oxygen Not Included\: the last lines usually name the failing mod exactly.
Frequently asked questions
Can mods be enabled from the mods menu on a pirated copy? Yes, the "Mods" menu works fully on any copy of the game. A fallback if the menu does not respond: the mods.json file in Documents\Klei\OxygenNotIncluded\mods — add an entry {"label":"<staticID from the mod's mod.yaml>","enabled":true} to the mods array; the staticID is visible in the mod manifest (for Fast Track it is PeterHan.FastTrack).
Do achievements work with mods? In Oxygen Not Included mods do not block achievements — you can keep earning them with a modded colony. The exception is Sandbox mode, which disables achievements on its own, regardless of mods.
Do mods need to be reinstalled after a game update? The files themselves do not change, but older mod versions may stop working on a new build — then just download a fresh release from the same source and replace the contents of the mod folder.