JankyBorders: Lightweight Window Border Customization Tool for macOS

JankyBorders is a lightweight tool designed specifically for macOS 14.0 and later, enabling users to add customizable colored borders to system windows. By visually distinguishing between active and inactive windows using different colors, it significantly improves the intuitiveness and efficiency of window management.

Key Features

1. Lightweight Design
   JankyBorders uses a minimal architecture to draw window borders directly via macOS private APIs, without relying on system accessibility interfaces. This results in faster startup and superior performance compared to similar tools.

2. Performance-Optimized
   Unlike traditional solutions that depend on the accessibility API, JankyBorders consumes minimal system resources. Real-time border updates are smooth and lag-free, ensuring no impact on overall system performance.

3. Highly Customizable

• Color Settings: Supports hexadecimal color format (e.g., 0xffe1e3e4), allowing separate colors for active and inactive windows
• Border Width: Adjustable border thickness (e.g., width=5.0)
• Style Options: Supports rounded corner borders (style=round)
• Display Mode: Control whether optimized display is enabled on HiDPI screens (hidpi=on/off)

4. Seamless Integration
   Perfectly compatible with popular window management tools:

• yabai: Easily integrated into yabairc configuration
• AeroSpace: Launchable via aerospace.toml configuration
• Other Tools: Runs as a standalone service, compatible with various workflows

5. Runtime Configuration
   Supports real-time updates to border properties without restarting the application—simply start a new borders instance to apply new settings.

Installation & Usage

Installation

Install via Homebrew with one command:

brew tap FelixKratz/formulae
brew install borders

Basic Configuration Example

Integrate with yabai (add to end of yabairc):

borders active_color=0xffe1e3e4 inactive_color=0xff494d64 width=5.0 &

Configuration File Support (Optional)

Create ~/.config/borders/bordersrc:

#!/bin/bash
options=(
    style=round
    width=6.0
    hidpi=off
    active_color=0xffe2e2e3
    inactive_color=0xff414550
)
borders "${options[@]}"

Service Management

Run as a system service via Homebrew:

brew services start borders

Technical Advantages

1. No Accessibility Dependency
   Does not rely on macOS accessibility API, eliminating complex permission requests while ensuring faster response times.

2. Open Source & Transparent Licensing
   Released under GPL-3.0, with fully transparent source code—users can review, modify, and distribute as needed.

3. Real-Time Update Mechanism
   Unique runtime configuration capability allows users to adjust border appearance without restarting applications or window managers.

4. Excellent Compatibility
   Designed for macOS 14.0+, leveraging modern macOS features while maintaining compatibility with legacy window management tools.

Ideal Users

• Window Management Enthusiasts: Enhance multi-window efficiency with yabai, AeroSpace, etc.
• Visual Professionals: Reduce window-switching errors through color differentiation
• Developers: Clearly distinguish between multiple code editors or terminal windows
• Productivity-Oriented Users: Improve window management experience without heavy software

Conclusion

JankyBorders fills a visual gap in macOS’s native window management with its lightweight, efficient, and highly customizable design. Whether you're an experienced developer or a general user seeking productivity improvements, this tool delivers intuitive window focus indicators at minimal system cost. It’s a valuable addition to the macOS window management ecosystem.

Note: Ensure your system is upgraded to macOS 14.0 or later before use. For detailed configuration options, consult the project Wiki or view full documentation via man borders.