A powerful network monitoring tool with real-time connection tracking and advanced filtering capabilities

Netstat Cat is a lightweight desktop application built with Tauri v2 and Rust, providing a user-friendly interface for monitoring network connections on macOS and Windows. It serves as a graphical replacement for the command-line netstat tool, making it easier to monitor network activity and identify which applications are using specific ports.

• Security & Privacy - Pure local operation with no network connections or data transmission

• Real-time Network Monitoring - Live display of active TCP/UDP connections

• Process Identification - Shows which processes own each network connection

• Advanced Filtering System - Search by process name, PID, port ranges, or semantic queries like process=chrome && lport>1000 See filtering guide

• Virtualized Table Performance - Efficiently handles large numbers of connections using React Virtuoso

• Lazy Process Resolution - Only fetches full executable paths when hovering over processes

• LRU Caching - Intelligent caching for process paths to avoid repeated system calls

• Modern UI - Frameless window with dark/light theme toggle

• Auto-refresh Mode - Configurable live monitoring (2-second intervals)

• macOS only (Homebrew)

brew install --cask xueshiqiao/tap/netstat-cat

• macOS and Windows (Direct Download)

Download from GitHub Releases: https://github.com/XueshiQiao/netstat-cat/releases

• macOS 10.15+ or Windows 10+
• Node.js 20+
• npm
• Rust (install via rustup)

# Clone the repository
git clone https://github.com/XueshiQiao/netstat-cat.git
cd netstat-cat

# Install dependencies
npm install

# Start Tauri development server (compiles Rust backend + starts Vite)
npm run tauri:dev

# Run type checking
npm run typecheck

# Run linting
npm run lint

# Build for current platform
npm run tauri:build

1. Launch the application to see all active network connections
2. Use the filter buttons to quickly narrow by protocol, IP version, or connection state
3. Enable auto-refresh for live monitoring

• Simple Search: Type process names, PIDs, or ports (e.g., chrome, 8080)
• Wildcards: Use * for pattern matching (e.g., *.exe)
• Port Ranges: Use ranges like 80-443
• Semantic Queries: Use advanced syntax like process=chrome && lport>1000

See filters_en.md for complete filtering documentation.

• React 19 with TypeScript
• Tailwind CSS for styling
• React Virtuoso for virtualized scrolling
• Vite for frontend bundling

• Tauri v2 for native desktop integration (uses OS webview, ~5MB binary)
• netstat2 crate for cross-platform socket enumeration
• sysinfo crate for PID-to-process name resolution
• Tauri IPC for communication between frontend and Rust backend

• Lazy loading of process paths
• Virtualized table rendering
• Efficient caching strategies
• Optimized system calls

Recommended: VSCode + ESLint + Prettier

netstat-cat/
├── src/                  # React frontend
│   ├── App.tsx           # Main UI component
│   ├── main.tsx          # Entry point
│   ├── assets/           # CSS and images
│   └── utils/            # Query parser, process cache
├── src-tauri/            # Rust backend
│   ├── src/
│   │   ├── lib.rs        # Tauri app setup & command registration
│   │   ├── netstat.rs    # Network socket fetching logic
│   │   └── process_info.rs  # Data structures
│   ├── Cargo.toml
│   └── tauri.conf.json   # Tauri configuration
├── index.html
├── vite.config.ts
└── resources/            # Icons and entitlements

• npm run tauri:dev - Start Tauri development mode
• npm run tauri:build - Build for production
• npm run typecheck - Run TypeScript type checking
• npm run lint - Run ESLint
• npm run format - Format code with Prettier

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Run tests and linting
5. Submit a pull request

This project is licensed under the GNU General Public License v3.0 - see the LICENSE file for details.

• Filtering Guide (English)
• 过滤指南 (中文)