Maximize Storage on Windows with CompactGUI: Easy NTFS Compression for Games & Apps

Modern Windows PCs face an ever-growing challenge as massive gaming titles and professional applications demand larger chunks of already limited storage space. While in the past, the main culprits of storage consumption were high-resolution textures and polygon-rich 3D models, the introduction of advanced graphics techniques such as ray tracing has pushed these requirements even higher. For users equipped with smaller SSDs or HDDs—not to mention cloud storage with metered quotas—every gigabyte counts. In this evolving landscape, effective data compression technologies can be a lifeline. One tool rising to prominence in this space, CompactGUI, has carved out a reputation for helping Windows users reclaim significant disk space, all while promising virtually no performance loss.

CompactGUI: The Power of Compression via GUI​

CompactGUI is a free, open-source utility that wraps Microsoft’s official NTFS file and folder compression feature—known as Compact.exe, introduced in Windows 10—in a user-friendly graphical interface. Instead of requiring users to brave the command line, CompactGUI translates these capabilities into a click-and-go experience, making NTFS compression broadly accessible. According to the developer, the tool leverages the native compression algorithms built into Windows, including several XPRESS profiles and the advanced LZX algorithm, and is able to transparently compress and decompress program files on-the-fly as applications run.
According to Microsoft's official documentation, NTFS compression is a core part of the Windows ecosystem and designed to be lossless, meaning that file contents are restored exactly when decompressed. This differentiates it from many everyday data compressors that may sacrifice speed or fidelity for volume savings. What's notable here is that CompactGUI is not introducing a new or unsupported technology; it is simply making an official Windows capability easier to use and more universally applicable.

Real-World Results: Compression with Minimal Performance Loss​

The claims made by CompactGUI’s developer—backed by user reports and XDA Developers’ own benchmarking—highlight meaningful storage gains for both games and productivity apps. Game folders that would have consumed significant space are seen to shrink by up to 60%, while applications like Adobe Photoshop drop to nearly half their original footprint. Let's delve into some specific examples drawn from verifiable reports:

• ARK: Survival Evolved: CompactGUI reportedly managed to compress the install from 169 GB to 91.2 GB, representing a compression ratio of approximately 0.54x.
• Adobe Photoshop: A typical install of 1.71 GB was reduced to 886 MB (ratio of 0.506x), showing that even complex productivity suites benefit.

XDA Developers extended testing to a variety of popular game titles, running comparisons using the different NTFS compression algorithms available through CompactGUI:

Game	Compression Type	Size Before (GB)	Size After (GB)	Compression Ratio
Baldur's Gate 3	XPRESS4K	142.62	130.78	0.92x
Baldur's Gate 3	XPRESS8K	146.18	129.92	0.89x
Baldur's Gate 3	XPRESS16K	145.90	129.78	0.89x
Baldur's Gate 3	LZX	152.71	134.54	0.88x
Counter-Strike 2	XPRESS4K	39.44	29.34	0.74x
Counter-Strike 2	XPRESS8K	36.18	26.28	0.73x
Counter-Strike 2	XPRESS16K	37.73	28.13	0.75x
Counter-Strike 2	LZX	38.17	27.04	0.71x
Little Kitty: Big City	XPRESS16K	13.76	6.34	0.46x
Little Kitty: Big City	LZX	13.43	5.44	0.40x
Cities: Skylines	XPRESS16K	13.06	7.08	0.54x
Cities: Skylines	LZX	13.27	6.30	0.47x
Half-Life: Alyx	XPRESS16K	72.93	61.60	0.84x
Half-Life: Alyx	LZX	72.52	58.08	0.80x

As these results reveal, the space savings can be substantial, especially for smaller or less intensely compressed titles. Larger AAA games, often subject to developer-side compression and asset optimization, tend to see more modest savings—though even there, multiple gigabytes are often reclaimed with no apparent performance cost.

Compression Algorithms in Focus​

The NTFS compression in Windows offers several algorithmic options:

• XPRESS4K, 8K, 16K: These are fast, general-purpose algorithms optimized for low overhead, using different chunk sizes. XPRESS4K is the default, offering a decent balance of compression and performance, while higher values (8K, 16K) can yield better compression at a slight processing cost.
• LZX: A more aggressive, high-ratio algorithm, LZX is best for maximum space saving but with increased CPU and RAM demands during decompression.

Recent third-party reviews and hands-on tests support the claim that, on modern processors—even aging models such as Intel’s i3-370M from 2010—the performance difference is virtually negligible. This is in line with Microsoft’s design: the overhead of decompression is meant to be small, particularly with SSDs, such that loading times may even improve due to reduced disk I/O, especially on traditional spinning HDDs.

Strengths and Notable Benefits​

Space Savings Without Sacrificing Speed​

The primary appeal of CompactGUI is its ability to recover disk space that would otherwise be consumed by low-compressibility assets. For users on smaller drives, especially laptops with 256 GB or less, such savings can postpone costly upgrades or cloud migrations. The tool is especially valuable for titles or programs that do not natively provide much compression or optimization for disk space.

Lossless and Easily Reversible​

There’s no loss of data integrity, as NTFS compression, by Microsoft’s own specification, is lossless. If space is later freed up, decompression can be easily reversed via the app or the command line, restoring files to their original state. This means users are not locked in or risking corruption, a concern common with third-party or proprietary compression schemes.

Universally Compatible with NTFS Volumes​

Because CompactGUI leverages a built-in Windows feature, it is compatible with all modern Windows editions—both Home and Pro—requiring only that target drives use the NTFS file system (the standard for internal Windows drives).

Straightforward User Experience​

The graphical interface targets power users and novices alike. Instead of memorizing verbose command-line switches and arguments, users can simply drag and drop folders, select desired compression settings, and apply the process with a click. Transparency into the process—showing what’s compressed, to what ratio, and recovery options—helps demystify storage optimization.

Potential Caveats and Risks​

Compatibility Concerns​

Not every use case or application is equally suited to post-install compression. The developer behind CompactGUI and several reviewers caution that certain categories—especially those relying on Microsoft’s DirectStorage API (used by cutting-edge games to directly stream assets from drive to GPU)—may actually experience issues or fail to realize any savings. DirectStorage is specifically designed to bypass the CPU for asset streaming, meaning compressed files may not be handled correctly, leading to crashes or corrupted loads.
Additionally, while no notable performance degradation has been reported in mainstream gaming or productivity scenarios, certain highly disk-dependent workloads or file types (particularly those already compressed, such as video or ZIP archives) may see negligible benefit or, in rare cases, added latency. As a best practice, it is recommended to test compression on non-essential files or use backup copies for mission-critical programs.

Resource Overhead​

While modern CPUs generally handle decompression in real-time with insignificant impact, older systems or those under severe CPU load may experience rare slowdowns, especially when using the more aggressive LZX algorithm. Systems with limited available RAM could also see minor increases in resource usage, as Windows caches decompressed content. Users on older hardware might want to opt for the faster XPRESS settings as a default.

Unsupported File Systems and Edge Cases​

CompactGUI is only operative on NTFS volumes. Drives formatted as exFAT, FAT32, or other alternatives are unsupported, so users with USB thumb drives, SD cards, or legacy system partitions won’t be able to take advantage. Furthermore, certain system folders are protected and cannot be compressed by user applications for security and stability reasons.

Future-Proofing and Updates​

Every system-level utility faces the risk of being rendered obsolete or incompatible as underlying OS technologies evolve. While NTFS compression has been a core Windows feature for decades, Microsoft could at any point alter its functionality or officially deprecate it, though there is no indication of this as of the time of writing. It’s advisable for users to monitor CompactGUI's GitHub repository for updates—especially as the app now requires .NET 9 runtime as a dependency, which represents a modest barrier for users on older systems or with tightly locked-down operating environments.

How to Try CompactGUI​

Users who wish to experiment with CompactGUI can safely download the latest release via its official GitHub repository. The process is straightforward:

• Install .NET 9 Runtime: Recent versions of CompactGUI require the .NET 9 framework. Download it from Microsoft’s official site if not already present.
• Download and Run CompactGUI: Obtain the zip or installer, extract or run, and follow the graphical prompts.
• Select Folders or Files: Drag and drop program or game folders into the interface.
• Choose Compression Algorithm: Opt for XPRESS4K (fastest and safest), XPRESS8K/16K (more compact, slightly slower), or LZX (maximum compression).
• Start Compression: The progress bar and summary stats display compression status and results.
• Revert if needed: Files can be decompressed in the same tool with a single click.

It's important to heed the developer's warnings: avoid compressing files used by DirectStorage-enabled games and consider running tests on a copy of critical program folders before committing changes system-wide.

Third-Party Reviews and User Experiences​

Multiple technology outlets, including Neowin and XDA Developers, have independently verified CompactGUI’s efficacy. Benchmarking with both indie and AAA games, as well as creative suites, revealed disk savings that match or sometimes exceed the developer's claims. Users frequently report that performance remains impressively stable, with loading times sometimes even improving, particularly on mechanical HDDs where reduced data footprint translates to less seeking.
Trustpilot and GitHub user feedback largely echo these findings, with the rare negative reviews most often tied to either hardware incompatibility (unsupported file systems) or misunderstandings about the limitations of NTFS versus third-party compression tools.

Final Assessment: A Powerful Space-Saving Asset for Windows Users​

The evidence drawn from verifiable sources is clear: CompactGUI stands as a unique example of harnessing official Microsoft technologies to deliver real-world, user-friendly benefits. Its ability to save disk space—sometimes dramatically—without performance loss marks it as an essential part of the savvy Windows user’s toolkit. Its reliance on native NTFS features ensures safety, reversibility, and broad compatibility, while the graphical interface democratizes what had previously been a power-user niche.
For gamers and professionals struggling with ballooning install sizes, CompactGUI offers a free and largely risk-free way to push back against ever-growing storage demands. The caveat, as always with system tools, is to proceed with a basic level of caution: test before deploying widely, avoid DirectStorage games, and be aware of your hardware’s limitations.
Ultimately, with the ongoing trend toward resource-hungry applications and games, demand for tools like CompactGUI is likely only to grow. For now, it provides an elegant, well-supported, and verifiable solution that stands on the shoulders of Microsoft’s robust NTFS implementation—making it one of the best-kept secrets for reclaiming disk space on Windows PCs.

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Source: Neowin Free app based on official Microsoft tech saves huge Windows space with no performance loss