Quake 4 reborn — modern systems, stunning visuals, the classic feel.
Features • Installation • Building • Documentation • Credits
OpenQ4 is a free, open-source replacement for the Quake 4 engine that brings your classic game into the modern era. Built on the shoulders of Quake4Doom, it keeps everything you love about the original — the brutal combat, the tight gameplay, the iconic atmosphere — and layers on a fresh set of visuals and quality-of-life upgrades that make it feel right at home on today's hardware.
Plug in a controller and play from the couch, enjoy crisp widescreen and ultrawide support, or push the visuals further with HDR rendering, dynamic shadow maps, and a suite of post-processing effects. The best part? It all runs on your existing copy of Quake 4 — no new assets, no subscription, just your game looking and playing better than ever.
Note
OpenQ4 does not include game assets. You must own a legitimate copy of Quake 4 to play. OpenQ4 is not compatible with legacy Quake 4 game mods.
OpenQ4 running with stock Quake 4 assets.
Getting up and running takes just four steps:
You'll need a copy of Quake 4 installed on your system. Grab it from Steam or GOG if you don't have it yet:
Head to the Releases page and download the latest archive for your platform (Windows, Linux, or macOS).
Unzip the archive to any folder you like.
Launch OpenQ4-client_x64 (that's OpenQ4-client_x64.exe on Windows). OpenQ4 will find your Quake 4 installation automatically — no fiddling with paths required in most cases.
Note
Windows players: The package is completely self-contained — no extra software needs to be installed.
Note
Linux players: OpenQ4 currently runs through XWayland on Wayland desktops. Make sure DISPLAY is set in your environment.
Tip
If OpenQ4 can't find your Quake 4 installation automatically, see the manual path configuration section in the technical reference.
Modern rendering upgrades running with original Quake 4 assets.
- HDR Rendering — Richer highlights and deeper shadows with filmic tone mapping; tweak exposure, contrast, saturation, and vibrance to taste
- Dynamic Shadow Maps (experimental) — Proper real-time shadows for lights throughout the game, with support for transparent surfaces
- Ambient Occlusion (SSAO) — Subtle contact shadows that add real depth to every environment
- Bloom — Natural light bleed around bright sources, tunable to stay tasteful or go dramatic
- CRT Emulation — Optional retro post-processing with scanlines, phosphor mask, screen curvature, and chromatic aberration — for that authentic late-2000s CRT look
- Modern Anti-Aliasing — MSAA and SMAA for smooth edges across a wide range of hardware
- Resolution Scaling — Dial down for performance on older machines, or push past native for supersampled sharpness
- Controller Support — Full gamepad play with plug-and-play hotplug, dual-stick aiming, and complete button remapping
- Widescreen and Ultrawide Ready — UI, field-of-view, and weapon framing all adapt automatically — no manual tweaks needed
- Multi-Monitor Support — Choose your display, let OpenQ4 auto-detect it, or go borderless windowed; it all just works
- Modern Fullscreen Modes — Exclusive fullscreen, borderless windowed, and desktop-native options to suit any workflow
- Single-Player and Multiplayer — The full Quake 4 experience in one engine, one install
- Smart Game Detection — Finds your Steam or GOG copy automatically and verifies your files at startup
- Runs Your Game Files — Designed from the ground up to work with your existing Quake 4 content — nothing replaced, nothing repackaged
- Modern Audio — Full positional 3D audio with WAV and Ogg Vorbis support
- Windows, Linux, macOS — One codebase, three platforms
- Display Settings — Multi-monitor and display configuration
- Shadow Mapping — Shadow quality, transparency, and troubleshooting
- Multiplayer Networking — Lag compensation and network tuning
- Technical Reference — Advanced configuration, compatibility status, file layout, dependencies, and versioning
Built for modern displays, modern GPUs, and modern systems without changing the original game feel.
Want to compile OpenQ4 yourself? Full instructions, compiler requirements, and notes on the OpenQ4-GameLibs companion repository live in BUILDING.md.
OpenQ4 is an open project and welcomes contributions of all kinds — bug reports, code fixes, new features, documentation, and platform testing.
- Fork the repository
- Create a feature branch
- Make your changes and test thoroughly
- Submit a pull request
Keep compatibility with official Quake 4 assets in mind, follow the existing code style, and see BUILDING.md for build setup instructions.
- themuffinator — OpenQ4 development and maintenance
- Justin Marshall — Quake4Doom, initial BSE reverse engineering
A massive thanks goes out to the Map-Center community for feedback on the project, particularly Papaya, JohnnyBoy and coffee009.
- id Software — idTech 4 engine and Quake 4
- Raven Software — Quake 4 game development
- Sean Barrett — stb_vorbis audio codec
- GLEW Team — Nigel Stewart, Milan Ikits, Marcelo E. Magallon, Lev Povalahev
- OpenAL Soft Contributors — 3D audio implementation
- SDL Team — Cross-platform framework
- Jorge Jimenez, Jose I. Echevarria, Belen Masia, Fernando Navarro, Diego Gutierrez — SMAA reference implementation and lookup textures
The Quake and id Tech community for continued support and enthusiasm, and all contributors who have submitted bug reports, patches, and improvements.
OpenQ4 is licensed under the GNU General Public License v3.0 (GPLv3). You are free to use, modify, and distribute the software under its terms.
See the LICENSE file for full details.
Note: The GPLv3 license applies to OpenQ4's engine code only. Game library code in OpenQ4-GameLibs is derived from the Quake 4 SDK and subject to id Software's EULA. Quake 4 game assets remain the property of id Software and ZeniMax Media.
OpenQ4 is an independent project and is not affiliated with, endorsed by, or sponsored by id Software, Raven Software, Bethesda, or ZeniMax Media. Quake 4 is a trademark of ZeniMax Media Inc.
You must own a legitimate copy of Quake 4 to use this software. OpenQ4 does not include any copyrighted game assets.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND. OpenQ4 is experimental software under active development. Use at your own risk.
Copyright © 2026 The OpenQ4 Project — Licensed under GPLv3.
Website • Repository • Game Library • Issue Tracker Releases • Quake 4 on Steam • Quake 4 on GOG • Map-Center on Discord
