800+ Games Supported

Nucleus Co-Op — Free Split-Screen for PC Games

Nucleus Co-Op (also searched as nucleus coop) is a free, open-source Windows app that adds split-screen multiplayer to games that don't support it natively — one PC, one copy of the game, multiple players.

"Adds remarkably smooth split-screen functionality to games that don't support it" — TechRadar
Download Nucleus Co-Op Installation Guide

800+

Supported Games

100%

Free & Open Source

Windows

7 / 10 / 11

0

Subscription Required

What is Nucleus Co-Op?

Nucleus Co-Op is a free and open-source tool for Windows that allows split-screen play on hundreds of PC games that do not initially support it. The application was originally created by developer Lucas Assis, then significantly expanded by Zerofox, Ilyaki, and Mikou27, each adding features like multi-keyboard/mouse support, extended hooks, and an overhauled user interface.

Today, Nucleus Co-Op is maintained by the SplitScreen.Me community and supports over 800 games through game setups — small configuration files that tell Nucleus how to launch, connect, and arrange each title for split-screen play.

The app launches multiple copies of the same game, assigns each player their own controller or keyboard, and connects the copies over your local network. It then resizes and positions the windows into a split-screen layout on your monitor.

Nucleus Co-Op does not add multiplayer to single-player games. The game must already have some form of LAN, online multiplayer, or a supported mod (like Skyrim Together Reborn) for Nucleus to connect the instances. It also does not crack or bypass DRM — you need a legitimate copy of the game.

The application is completely free to download and use. The project is sustained by optional Patreon donations from the community. All source code is available on GitHub.

Is Nucleus Co-Op safe?

Yes. Some support files may trigger antivirus false positives. Add your Nucleus folder to Microsoft Defender exclusions before extracting. The project is 100% open source.

Is Nucleus Co-Op legal?

Yes. It requires you to own a legitimate copy of each game. It does not distribute game files or bypass copy protection.

How Nucleus Co-Op Works

Multiple Game Instances

Nucleus launches two or more copies of the same game on your PC simultaneously. Each instance responds only to one assigned controller, keyboard, or mouse.

Local Multiplayer Connection

Game copies connect over your local network so you can play together without an internet connection.

Automatic Window Layout

Nucleus removes window borders and automatically resizes and positions each game window to create a split-screen layout — horizontal, vertical, or custom grid.

Per-Game Setups

Each supported game has a setup file that tells Nucleus how to configure that title. Download setups from the game library inside Nucleus or at hub.splitscreen.me.

Multi-Input Support

Works with Xbox-style controllers, PlayStation controllers (via DS4Windows), and multiple keyboards and mice where supported.

Separate Controls Per Player

Nucleus routes each controller, keyboard, or mouse to the correct game window so players do not interfere with each other.

Popular Nucleus Co-Op Games

View all 800+ games
Halo: The Master Chief Collection split-screen with Nucleus Co-Op

Halo: The Master Chief Collection

2-4 Players Steam Easy
Elden Ring split-screen with Nucleus Co-Op

Elden Ring

2 Players Steam Medium
Minecraft Java Edition split-screen with Nucleus Co-Op

Minecraft Java Edition

2-4 Players Launcher Medium
Grand Theft Auto V split-screen with Nucleus Co-Op

Grand Theft Auto V

2 Players Steam Medium
Grounded split-screen with Nucleus Co-Op

Grounded

2-4 Players Steam Easy
Left 4 Dead 2 split-screen with Nucleus Co-Op

Left 4 Dead 2

2-4 Players Steam Easy
Call of Duty: Black Ops 2 split-screen with Nucleus Co-Op

Call of Duty: Black Ops 2

2-4 Players Steam / Plutonium Medium
Call of Duty: Black Ops 3 split-screen with Nucleus Co-Op

Call of Duty: Black Ops 3

2-4 Players Steam Medium
Borderlands 2 split-screen with Nucleus Co-Op

Borderlands 2

2-4 Players Steam Easy
Enshrouded split-screen with Nucleus Co-Op

Enshrouded

2-4 Players Steam Easy
Risk of Rain 2 split-screen with Nucleus Co-Op

Risk of Rain 2

2-4 Players Steam Easy
Deep Rock Galactic split-screen with Nucleus Co-Op

Deep Rock Galactic

2-4 Players Steam Easy

Get Started in 4 Steps

01

Download Nucleus

Get the latest NucleusApp.zip from the official GitHub releases page.

02

Extract to C:\

Extract to C:\NucleusCo-op using 7-Zip (password: nucleus). Add to Defender exclusions first.

03

Add Your Game

Search for your game in Nucleus and install its game setup from the library.

04

Assign Inputs & Play

Drag your controllers to each screen section, click Play, and enjoy split-screen.

Frequently Asked Questions

What is Nucleus Co-Op? +
Nucleus Co-Op is a free, open-source Windows tool that adds split-screen to PC games that do not support it out of the box. It runs multiple copies of the same game on one PC, connects them for co-op play, and arranges the windows so each player has their own view.
Is Nucleus Co-Op safe to use? +
Yes. Nucleus Co-Op is safe when downloaded from the official GitHub page. Some antivirus tools, including Microsoft Defender, may flag support files as false positives. Add your Nucleus folder to Defender exclusions before extracting.
Is Nucleus Co-Op legal? +
Yes. You must own a legitimate copy of each game. Nucleus does not bypass copy protection or distribute game files — it only runs games you already own on one PC.
Is Nucleus Co-Op free? +
Yes, Nucleus Co-Op is completely free and open source on GitHub. Optional Patreon donations help support development.
Does Nucleus Co-Op work with pirated games? +
Game setups are built and tested for legitimate Steam copies. Unofficial copies may be missing files or Steam features, so compatibility is not guaranteed.

More questions? See the full FAQ or visit the community subreddit.