For demos, screencasts and recorded lessons
Install SeventyKeys, click "Show my keystrokes" and grant Accessibility access once: every shortcut you type afterwards appears large, at the bottom (or top) of the screen, in a dark cartouche that fades on its own after one to three seconds. It's exactly what you need for a screencast, a live demo, or a recorded lesson: your audience sees what you're doing on the keyboard without you having to say it out loud.
Download the free SeventyKeys trial (7 days, macOS 13+).
To know that a key was pressed, macOS offers only one technical path: a CGEvent tap, gated by the Accessibility authorization. SeventyKeys uses it in READ-ONLY mode (.listenOnly): the app cannot modify, block, or replay a keystroke. Nothing is recorded, nothing is written to disk, nothing is sent over the network.
In settings, pick the position (bottom or top of screen), the text size (S/M/L), and the display duration. The "shortcuts only" option is checked by default and strongly recommended: unchecked, every key you press is shown, including inside a password field.
Get SeventyKeys: 7-day trial, then a lifetime license.