Beautiful interactive snowfall overlay for macOS
A lightweight menubar app that brings winter magic to your desktop with GPU-accelerated snowflakes that interact with your windows.
Features • Installation • Demo • Configuration • Privacy
- 🎨 GPU-Accelerated Rendering — Powered by Metal for smooth performance with thousands of particles
- 🪟 Window Collision Physics — Snowflakes realistically melt when landing on window borders
- 🖱️ Mouse Interaction — Snowflakes react dynamically to cursor movement
- 🌬️ Wind Simulation — Adjustable wind strength affects snowflake trajectories
- 🖥️ Multi-Monitor Support — Works seamlessly across all connected displays
- 3 Built-in Presets: Light Snow, Comfortable Background, Blizzard
- Granular Controls:
- Speed range (0.1–8.0)
- Size range (1–25)
- Particle count (100–10,000)
- Wind strength (0–500)
- Privacy-Focused — All processing happens locally; no data collection
Get automatic updates via Homebrew:
brew install --cask barredewe/cask/snowfall
- Download the latest release from Releases
- Unzip and move
Snowfall.appto/Applications - Launch and grant Screen Recording permission when prompted
Access settings via the menubar icon (❄️):
| Mode | Particles | Speed | Size | Wind | Best For |
|---|---|---|---|---|---|
| Light Snow | 800 | 0.2–1.5 | 2–12 | 0.5 | Minimal distraction |
| Comfortable | 2,000 | 0.5–3.0 | 3–15 | 1.0 | Balanced aesthetics |
| Blizzard | 6,000 | 2.0–8.0 | 2–20 | 4.0 | Maximum winter vibes |
| Custom | — | — | — | — | Manual tuning |
Window Interaction
Toggle collision physics for performance-critical workflows. When enabled:
- Uses
CGWindowListCopyWindowInfoAPI to detect window positions - Processes data in RAM only (no recording/storage)
- Snowflakes melt gradually upon contact
Mouse Influence Radius: 50px default
- Language: Swift 5.9+ with SwiftUI
- Graphics: Metal API for compute & render pipelines
- Physics: Custom particle system with SIMD2 vectors
- Platform: macOS 11.0+ (Big Sur and later)
SnowfallApp/
├── Common/
│ ├── Views/
│ │ ├── MenuBarSettings.swift # SwiftUI preferences UI
│ │ └── MetalSnowViewController.swift # MTKView controller
│ ├── Settings.swift # Codable configuration
│ ├── Snowflake.swift # Particle data structure
│ ├── SnowRenderer.swift # Metal pipeline manager
│ └── WindowInfo.swift # CGWindowListCopyWindowInfo wrapper
├── SnowfallApp.swift # App entry point
└── SnowShader.metal # GPU kernels (compute + render)
- Compute Shader: Parallel particle updates on GPU
- Instanced Rendering: Single draw call for all particles
- Adaptive Caching: Window positions refreshed every 500ms
- Point Primitives: Efficient anti-aliased circles via fragment shader
- Xcode 15.0+
- macOS 13.0+ SDK
- Swift 5.9+
# Clone repository
git clone https://github.com/barredewe/snowfall.git
cd snowfall
# Open in Xcode
open Snowfall.xcodeproj
# Build & Run (⌘R)
Zero Data Collection Policy
Snowfall operates entirely offline:
- ✅ No network requests
- ✅ No analytics/tracking
- ✅ No third-party SDKs
- ✅ All settings stored locally (
UserDefaults)
Permissions Explained:
- Screen Recording: Required only for window collision detection
- Accessibility: Alternative permission for older macOS versions
See PRIVACY.md for full policy.
Contributions are welcome!
Development Setup:
- Fork the repository
- Create feature branch (
git checkout -b feature/amazing-feature) - Follow Swift API Design Guidelines
- Submit PR with detailed description
Apache 2.0 License - see LICENSE for details.
- Metal framework by Apple
- Inspiration from classic screensavers
- Icon design: SF Symbols
Barredewe
📮 barredewe@gmail.com
🐙 GitHub
If you enjoy Snowfall, please ⭐ star this repository!
Made with ❄️ in Russia