Rectangle is one of the most popular free window management apps for macOS. It lets you snap, resize, and arrange windows using keyboard shortcuts or by dragging them to the edges of your screen — no mouse precision required. It is open-source, lightweight, and the first thing many Mac users install on a new machine.

Key Features:

• Snap windows to halves, thirds, quarters, sixths, and eighths of the screen
• Fully customizable keyboard shortcuts for every window action
• Drag windows to screen edges or corners to snap them instantly
• Supports multiple displays and multi-monitor setups
• Cycle through window sizes by repeating the same shortcut
• Free and open-source — no ads, no tracking, no subscription
• Rectangle Pro available for $9.99 with custom layouts, iCloud sync, and more