About Compact GUI
An independent resource dedicated to the disk compression tool that reclaims storage space without sacrificing performance.
If you have ever stared at a nearly full hard drive and wondered which games or apps to uninstall, CompactGUI offers a different answer: keep everything, just make it smaller. This open-source Windows utility wraps the built-in NTFS transparent compression engine in a clean, drag-and-drop interface—letting anyone reclaim tens of gigabytes without deleting a single file.
Compact GUI exists because we think more people should know about this tool. We are not the developers. We are users who got tired of juggling storage and want to help others find the same solution.
The Story Behind CompactGUI
From a single developer’s side project to a tool trusted by hundreds of thousands of Windows users.
The Beginning
Developer IridiumIO noticed that Windows ships with a powerful but hidden compression tool called compact.exe. The command-line interface kept most people from ever using it. IridiumIO set out to build a graphical front-end that anyone could pick up.
Gaining Traction
Word spread on Reddit and gaming forums. Gamers discovered they could compress Steam libraries by 30-60% with virtually no performance hit. The community compression database started taking shape as users submitted their results.
Major Growth
CompactGUI added the Background Watcher service for automatic recompression after game updates, Windows Explorer context menu integration, and winget install support. The GitHub repository passed thousands of stars.
Version 3.8 and Beyond
The stable v3.8 release arrived in February 2025. A v4.0 beta introduced .NET 9 support and a refreshed interface. The community database now holds over 9,700 tested games with more than 82,000 compression submissions.
What CompactGUI Actually Does
Transparent NTFS compression that shrinks files on disk while keeping them fully accessible to every application.
Transparent Compression
Files stay exactly where they are and work with every application. Windows decompresses them on the fly when accessed. No zipping, no extracting, no extra steps.
Four Algorithms
Choose between XPRESS4K, XPRESS8K, XPRESS16K, and LZX. Faster options for SSDs, stronger compression for older drives. Each balances speed against space savings differently.
Community Database
Over 9,700 games and 82,000 submissions. Before you compress anything, check what other users achieved with the same software—expected ratios, recommended algorithms, and any known issues.
Background Watcher
Game updates often replace compressed files with uncompressed ones. The Background Watcher service detects changes and recompresses automatically, so savings persist through every patch.
The Developer
CompactGUI is built and maintained by a single developer under the GPL-3.0 open-source license.
IridiumIO
IridiumIO develops CompactGUI on GitHub as an open-source project. The tool grew from a personal need: a straightforward way to use Windows’ built-in compact.exe without memorizing command-line flags. Development has been steady since 2016, with regular releases, responsive issue tracking, and active community engagement.
The project is licensed under GPL-3.0, meaning anyone can inspect, modify, and redistribute the source code. Contributions come from the community, and compression results are crowd-sourced from users around the world.
View on GitHubWhy People Rely on It
For gamers with packed SSDs and laptop users watching every gigabyte, CompactGUI has become a quiet essential.
Unlike alternatives such as Compactor (which is command-line focused) or SNUG (a paid Steam tool), CompactGUI is free, open-source, and works on any folder—not just Steam games. Users frequently report reclaiming 50-100 GB on gaming drives without any noticeable performance difference.
The tool fills a gap that Windows itself created. NTFS compression is a powerful feature baked into the operating system, but Microsoft never built a user-friendly way to apply it selectively. CompactGUI does exactly that.
About This Website
Compact GUI is an independent resource. Here is what that means.
This website is not affiliated with, endorsed by, or connected to IridiumIO or the CompactGUI project in any way. We are an independent fan-made informational resource.
We provide guides, tutorials, and clear explanations to help users get started with CompactGUI and get the most out of it.
Every download link on this site points to the official GitHub releases page. We never host, modify, or redistribute the software.
We encourage every user to visit the official GitHub repository, star the project, and contribute to the community database.
Get in Touch
Have a question about this website or found something that needs correcting?
Visit our Contact page to reach us. For official CompactGUI support, bug reports, or feature requests, head to the GitHub Issues page.