KeyCastr

KeyCastr is a free, open-source keystroke visualizer for macOS. It shows your keyboard shortcuts on screen as you press them — a floating overlay that displays each key combination in real-time. When you press Cmd+Shift+P, the overlay shows '⌘⇧P' on your screen. The primary use case is screencasting. When you record a tutorial, your viewers can't see your keyboard. They watch your cursor move and things happen on screen, but they don't know what you pressed. KeyCastr solves this by displaying each keystroke as a visual overlay on your recording. A coding tutorial becomes more useful when viewers see 'Cmd+P' appear when you open the command palette, or 'Cmd+S' when you save. The second use case is live presentations. During a demo or conference talk, the audience watches your screen on a projector. They can follow along much better when they see which shortcuts you're using. This is especially true for presentations about tools, editors, or development workflows where keyboard shortcuts are the point. KeyCastr is highly customizable. Choose the position (any corner or center), font size, colors, opacity, fade duration, and whether to show individual keys or full modifier combinations. You can filter which keys are displayed — show only modifier combinations (Cmd+X, Ctrl+C) while hiding regular typing. This prevents the overlay from showing every letter you type in a text editor, which would be distracting and potentially reveal sensitive content. The app is lightweight: it runs in the menu bar, displays an overlay on key events, and uses minimal resources. There's no recording, no analytics, no network access. It reads keyboard events through macOS Accessibility APIs, which means you need to grant Accessibility permission in System Settings. KeyCastr is completely free and open-source (BSD license). There's no paid tier, no registration, no feature limits. It's maintained by a small community on GitHub and receives updates for macOS compatibility. The honest take: KeyCastr does one thing and does it well. If you make screencasts, record tutorials, or give live presentations where keyboard shortcuts matter, KeyCastr is exactly the tool you need. If you don't do those things, you'll never need it. It's a niche tool that's perfect for its niche.