Key Codes is a little utility that displays the key code, unicode value, and modifier keys state for any key combination you press. If you're a developer, this might be useful to you.
Added a popover that breaks modifier flags down into known constants and their values.
Most Helpful Reviews
Indispensible - If you do anything involving modifier codes, key codes, hot keys, etc, then installing Key Codes should be a no-brainer. It's definitely earned its spot amongst my developer tools.
not all keys - The app reports most standard keys; however, the play/pause keys and the volume control keys, etc., do not show up.
More Reviews for Current Version
Perfect - Works like a charm!
excellent - does just what it says. Thanks!
Incredibly useful tool - Great app; I've been wanting something like this for a long time. Plus it's free!
Exactly what I needed! - I have a Kinesis Advantage2 ergonomic keyboard, and this app is perfect for trouble-shooting issues with remapping keys on this programmable keyboard. For instance, I thought that something had broken to get rid of one of my keyboard short-cuts, and initially I blamed software. After quite a bit of time trying to find the problem, I finally narrowed it down to a bug in the keyboard driver that had reconfigured one of my keys so that it was sending ALT instead of CTRL. Without this app, it would have been MUCH tougher to diagnose the problem! I've been using this app since OS X "El Capitan", and it has worked flawlessly with every new release. I'm currently running macOS 10.12.6, and it works great.
Great tool - Haven’t used other versions, but this does exactly what it needs to do - saved me hours of programming a utility to do soemthing similar (and not nearly as well). Thank you