GitHub - sm18lr88/win-folder-size: Display folder sizes in Windows Explorer's Size column via a lightweight COM shell extension

FolderSize

Display folder sizes in Windows Explorer.

Prerequisites

Runtime

Windows 10/11 x64
Everything 1.5a with folder-size indexing enabled

Build

Visual Studio 2022+ (MSVC)
CMake 3.20+
vcpkg with VCPKG_ROOT set

Quick Install

Download foldersize-vX.X.X-win64.zip from Releases
Extract and run install.bat as Administrator
Folder sizes appear immediately

Building from Source

git clone https://github.com/sm18lr88/win-folder-size.git
cd win-folder-size
scripts\build.bat          :: Release build
scripts\build.bat Debug    :: Debug build (verbose logging)

Output: build\foldersize.dll

Install / Uninstall

All scripts require Administrator privileges.

scripts\install.bat        :: Register DLL + restart Explorer
scripts\uninstall.bat      :: Unregister + restart Explorer
scripts\status.bat         :: Check COM registration and Everything status

Manual uninstall: regsvr32 /u foldersize.dll

Comparison with Windhawk "Better File Sizes"

Feature	Windhawk	FolderSize
Folder sizes in Details view	✓	✓
Folder sizes in Tiles / Content / Details-pane / Status bar	✓	✓
Reparse point / junction / symlink resolution	partial	✓
`PSFormatForDisplay` (legacy dialogs)	✓	✓
Cache invalidation on filesystem changes	✗	✓
SEH protection on all hooks	✗	✓
RAII recursive-op guard	✗	✓
Bounded LRU cache	✗	✓ (50 MB, 5-min TTL)
Loading mechanism	Windhawk service	`regsvr32` — standard COM
Uninstallation	Requires Windhawk	`regsvr32 /u`
Extension footprint	Windhawk mod	Single DLL, 144 KB
Required runtime	Windhawk	Everything

Acknowledgements

This project was inspired by m417z's excellent Better file sizes in Explorer details Windhawk mod, which pioneered the hook targets and approach used here. If you're already using Windhawk, that mod is a great option.

Technical Details

For how the hooks work, architecture, and performance benchmarks, see docs/technical-overview.md.

License

MIT