active-keys

Know and listen for which keys the user is currently holding down using standard KeyboardEvent#key values.

npm install --save active-keys

import keyWatcher from 'active-keys';
keyWatcher.addEventListener('change', () => {
  console.log(Object.keys(keyWatcher.activeKeys));
});

• Even handles multiple of the same key held down (e.g. down right Alt, then down left Alt, and then up left Alt - will still indicate Alt down).
• Includes React helper.
• Requires support for Set and KeyboardEvent#key.
• Will err on the side of indicating that a key is inactive.

Live Example