MacDirStat

Free, open-source disk space analyzer for macOS — like WinDirStat, but native to the Mac.

Find out what's eating your storage with interactive treemap visualizations, just like WinDirStat and WizTree on Windows. MacDirStat is a fast, lightweight, native macOS app built with SwiftUI — no Electron, no subscriptions, no tracking.

Why MacDirStat?

• Free and open source — no paywall, no trial limits, no ads
• Native macOS app — built with SwiftUI, feels right at home on your Mac
• Fast scanning — uses low-level BSD fts APIs for speed that beats FileManager-based tools
• Zero dependencies — nothing to install, no runtimes, no frameworks to download
• Privacy-first — runs entirely offline, never phones home

If you've used WinDirStat, WizTree, or TreeSize on Windows and want the same experience on macOS, MacDirStat is the answer. It's also a great free alternative to DaisyDisk, GrandPerspective, and OmniDiskSweeper.

Features

• Interactive Treemap Visualization — Squarify algorithm renders directories and files as proportionally-sized, color-coded rectangles
• Directory Tree Sidebar — Hierarchical outline view for browsing the file tree alongside the treemap
• File Inspector — Detail panel showing file size, allocated size, file/directory counts, modification dates, and a category breakdown chart
• Breadcrumb Navigation — Drill down into subdirectories and navigate back via breadcrumb bar
• 10 File Categories — Documents, Images, Video, Audio, Code, Archives, Applications, System, Caches, and Other — each with distinct colors
• Size Metric Toggle — Switch between file size and allocated (on-disk) size
• Volume Picker — Launch screen shows mounted drives with usage bars, or scan any custom folder
• Zoom & Pan — Scroll to zoom into dense treemap regions
• Reveal in Finder — Jump to any file or folder directly from the inspector
• Copy Path — One-click path copying to clipboard

Installation

Build from source

Requires macOS 15.0+ and Swift 6.

git clone https://github.com/phalladar/MacDirStat.git
cd macdirstat
swift build -c release
swift run MacDirStat

Or open in Xcode:

open Package.swift

Zero external dependencies. Pure Swift Package Manager project.

Architecture

MacDirStat is built with SwiftUI and Swift 6 strict concurrency. A single @Observable AppState drives all views.

Scan pipeline: User picks a folder → ScanCoordinator launches FileScanner → FileScanner uses BSD fts_open/fts_read/fts_close for fast traversal → streams ScanEvents via AsyncStream → coordinator throttles UI updates at 50ms intervals → treemap renders.

Project Structure

Sources/MacDirStat/
├── App/              # Entry point, AppState
├── Scanning/         # FileScanner (BSD fts), ScanCoordinator, FileNode tree model
├── Categorization/   # FileCategory definitions, 200+ extension mappings
├── Treemap/          # Squarify layout engine, Canvas renderer, hit testing
├── Views/            # ContentView, WelcomeView, DirectoryTreeView, DetailPanelView
└── Utilities/        # ByteFormatter

Contributing

Contributions are welcome! Open an issue or submit a pull request.

Related Projects

• WinDirStat — the original Windows disk usage analyzer
• WizTree — fast disk space analyzer for Windows
• GrandPerspective — treemap disk visualizer for macOS
• DaisyDisk — commercial macOS disk analyzer