For years, Windows users have lamented a glaring omission in File Explorer's functionality: the inability to display folder sizes in the Details view. While individual file sizes appear instantly, folders remain frustratingly blank in the Size column, forcing users to right-click and select Properties for each directory they want to measure. This workflow interruption has persisted through multiple Windows versions, becoming one of the most requested features that Microsoft has never implemented natively. However, the developer community has stepped in with an ingenious solution that combines two powerful tools: the lightning-fast search engine Everything and the modification platform Windhawk. This combination doesn't just patch the missing feature—it creates a superior implementation that outperforms what many users imagined possible.

The Core Problem: Why Explorer Doesn't Show Folder Sizes

Windows Explorer's limitation isn't an oversight but a deliberate design choice rooted in performance considerations. Calculating folder sizes recursively requires scanning every file within a directory and all its subdirectories—an operation that becomes increasingly resource-intensive as folder structures grow. For directories containing thousands of files or nested subfolders, real-time size calculation could significantly slow down navigation, especially on traditional hard drives. Microsoft's solution has been to make size calculation an explicit user action (via Properties) rather than an automatic background process. While this preserves interface responsiveness, it creates substantial workflow friction for power users, IT professionals, and anyone who regularly manages large collections of files.

Enter Everything: The Search Engine That Changes Everything

At the heart of this solution is Everything, a freeware search utility developed by David Carpenter that has achieved legendary status among Windows power users. Unlike Windows Search, which can be sluggish and incomplete, Everything uses the NTFS file system's USN Journal to maintain a real-time index of all files and folders. According to official documentation, this approach allows Everything to return search results "instantly" as you type, with minimal system impact. The application's efficiency comes from reading the Master File Table (MFT) directly rather than crawling the file system conventionally. This architectural difference means Everything already knows where every file is located and how large it is—information that can be repurposed to calculate folder sizes almost instantaneously.

Everything's relevance to the folder size problem becomes clear when you consider its folder size calculation capability. Through its application programming interface (API) and command-line interface, Everything can query the total size of any directory by summing the sizes of all contained files. Because it references its pre-built index rather than scanning the file system anew, this calculation happens remarkably fast—often in milliseconds even for directories containing tens of thousands of files. This performance makes Everything an ideal backend for a folder size display solution, eliminating the performance concerns that likely prevented Microsoft from implementing the feature natively.

Windhawk: The Modification Platform That Bridges the Gap

While Everything provides the computational engine, it needs a way to integrate its capabilities directly into Windows Explorer's interface. This is where Windhawk enters the equation. Developed as an open-source platform for modifying Windows applications, Windhawk allows developers to create "mods" that alter program behavior without requiring access to source code. Unlike traditional application patching, Windhawk mods are generally safer and more reversible, operating through carefully engineered hooks rather than binary modification.

The specific Windhawk mod that enables folder size display works by intercepting Explorer's requests for item information in the Details view. When Explorer queries for the size of a folder item, the mod redirects that request to Everything's engine instead of returning null or triggering a manual scan. This integration happens seamlessly in the background—users see folder sizes appear in the Size column exactly where file sizes appear, with no apparent delay or interface disruption. The mod handles various Explorer scenarios including refresh operations, navigation between folders, and sorting by the Size column, maintaining consistency with native Explorer behavior.

Technical Implementation: How the Integration Works

The technical marriage between Everything and Windhawk represents a sophisticated example of Windows ecosystem innovation. The implementation involves several key components working in concert:

  • Everything Service: Runs in the background maintaining the file index and responding to size queries
  • Windhawk Mod: Injects code into Explorer.exe process to intercept property requests
  • Communication Bridge: Facilitates data exchange between the mod and Everything (often through Everything's command-line interface or SDK)
  • Caching Layer: Stores recently calculated folder sizes to avoid redundant queries

When a user navigates to a folder in Details view, the following process occurs:

  1. Explorer prepares to display folder contents and requests properties for each item
  2. The Windhawk mod intercepts requests for folder size properties
  3. For each folder, the mod queries Everything's index for the total size of all contained files
  4. Everything returns the calculated size from its pre-computed data
  5. The mod supplies this value to Explorer, which displays it in the Size column

This process typically completes before the user would notice any delay, with folder sizes appearing as quickly as file sizes. The system intelligently handles edge cases like permission-restricted folders, network locations, and removable media, falling back gracefully when Everything cannot access certain paths.

Performance Considerations and System Impact

One might reasonably question whether this solution introduces the very performance problems Microsoft sought to avoid. In practice, the Everything-Windhawk combination proves remarkably efficient for several reasons. First, Everything's index-based approach means folder size calculations are mathematical summations rather than disk-intensive operations. Second, the Windhawk mod can implement intelligent caching—once a folder's size is calculated, that value can be reused until the folder's contents change. Third, the solution can be configured to calculate sizes only for visible folders rather than entire directory trees, minimizing unnecessary computation.

According to performance testing by users on forums and technical communities, the overhead of running Everything is minimal—typically consuming 10-50MB of RAM and negligible CPU during normal operation. The Windhawk mod adds virtually no measurable overhead since it merely redirects existing Explorer function calls. Compared to the alternative of manually checking properties for multiple folders, the time savings are substantial, especially for users who regularly work with complex directory structures.

Installation and Configuration Process

Implementing this folder size solution requires installing and configuring both components:

Everything Installation:

  1. Download Everything from voidtools.com
  2. Run the installer or portable version
  3. Launch Everything and allow it to build the initial index (this may take several minutes on first run)
  4. Configure Everything to start with Windows for persistent availability

Windhawk Mod Installation:

  1. Install Windhawk from windhawk.net
  2. Open Windhawk and browse the mod marketplace
  3. Search for "folder size" or "Everything" to find the relevant mod
  4. Install the mod and ensure it's enabled

Configuration Steps:

  • Verify Everything is running and accessible
  • Configure the Windhawk mod to point to Everything's installation path if necessary
  • Restart File Explorer or log out and back in to activate the integration
  • Test by navigating to folders in Details view—sizes should appear within seconds

Some users report needing to configure Everything to run as a service or with elevated privileges for certain protected folders. The mod typically includes configuration options for refresh intervals, size formatting (bytes, KB, MB, etc.), and handling of special folder types.

User Experiences and Community Feedback

Windows enthusiasts who have implemented this solution report overwhelmingly positive experiences. On forums like WindowsForum.com and Reddit's r/Windows10 and r/Windows11 communities, users describe the integration as "transformative" for file management workflows. IT professionals particularly appreciate the ability to quickly identify space-hogging directories without resorting to third-party disk analysis tools. Graphic designers, video editors, and developers—who often work with projects containing thousands of files across deep directory structures—report significant time savings in managing their assets.

Some users have noted occasional synchronization delays when files are added or modified outside of Everything's monitoring scope, though these typically resolve within seconds as Everything updates its index. A small subset of users with highly restricted system permissions have reported compatibility issues, usually resolvable through configuration adjustments. The consensus among technical communities is that this solution represents one of the most valuable quality-of-life improvements available for Windows file management.

Comparison with Alternative Solutions

Several other approaches to displaying folder sizes exist, each with different trade-offs:

Third-Party File Managers

Applications like Directory Opus, Total Commander, and XYplorer include folder size calculation as native features. While comprehensive, these require abandoning Windows Explorer entirely, which many users are reluctant to do for consistency reasons.

Explorer Extensions

Shell extensions like Folder Size add a separate column to Explorer but typically suffer from the performance issues Microsoft sought to avoid—they often freeze Explorer while calculating sizes for large directories.

PowerShell Scripts

PowerShell can calculate folder sizes efficiently but requires manual execution and doesn't integrate into Explorer's interface.

Built-in Workarounds

The Storage Sense feature in Settings provides folder size information but only for major user directories, not arbitrary folders in Explorer.

The Everything-Windhawk solution uniquely combines the performance of a dedicated indexer with the seamless integration of a shell mod, offering the best of both worlds without replacing core Windows components.

Limitations and Considerations

While powerful, this solution has some limitations worth noting:

  • NTFS Dependency: Everything relies on NTFS features and works best with local NTFS drives. FAT32, exFAT, and network drives may have limited functionality.
  • Initial Indexing Time: Building Everything's initial index can take time on systems with millions of files, though this is a one-time cost.
  • Administrator Requirements: Some configurations require administrator privileges for proper operation.
  • Update Compatibility: Major Windows updates occasionally break Windhawk mods until they're updated by developers.
  • Security Software Interference: Some antivirus programs may flag the injection techniques used by Windhawk, requiring exclusions.

Despite these considerations, for most users on modern Windows systems with NTFS drives, the solution works flawlessly with minimal setup.

The Future of Windows File Management

The success of this community-driven solution highlights both a persistent user need and the innovative potential of Windows' enthusiast community. While Microsoft has introduced various file management improvements in recent Windows versions—including tabs in Explorer, improved search, and better cloud integration—the folder size omission remains unaddressed in stock Windows 11. The Everything-Windhawk integration demonstrates that the technical barriers to implementation are surmountable with clever engineering.

Looking forward, this approach could inspire similar enhancements to Windows Explorer. The same combination of efficient indexing and lightweight modification could potentially add columns for file counts within folders, duplicate file detection, or custom metadata display. The modular approach means users can selectively enhance Explorer with only the features they need rather than adopting monolithic third-party replacements.

For now, Windows users seeking folder sizes in Explorer have an elegant, efficient solution that finally closes one of the platform's longest-standing functionality gaps. By combining Everything's legendary indexing speed with Windhawk's precise modification capabilities, the Windows community has delivered what Microsoft hasn't—and in doing so, has created a file management enhancement that feels so natural, users quickly forget it wasn't always there.