Can I use
?

KeyboardEvent.getModifierState()

- WD

KeyboardEvent method that returns the state (whether the key is pressed/locked or not) of the given modifier key.

Chrome

  1. 4 - 29: Not supported
  2. 30 - 112: Supported
  3. 113: Supported
  4. 114 - 116: Supported

Edge

  1. 12 - 112: Supported
  2. 113: Supported

Safari

  1. 3.1 - 10: Not supported
  2. 10.1 - 16.4: Supported
  3. 16.5: Supported
  4. 16.6 - TP: Supported

Firefox

  1. 2 - 14: Not supported
  2. 15 - 112: Supported
  3. 113: Supported
  4. 114 - 115: Supported

Opera

  1. 9 - 11.6: Not supported
  2. 12: Support unknown
  3. 12.1: Supported
  4. 15 - 16: Not supported
  5. 17 - 98: Supported
  6. 99: Supported

IE

  1. 5.5 - 8: Not supported
  2. 9 - 10: Supported
  3. 11: Supported

Chrome for Android

  1. 113: Supported

Safari on iOS

  1. 3.2 - 10.2: Not supported
  2. 10.3 - 16.4: Supported
  3. 16.5: Supported

Samsung Internet

  1. 4 - 20: Supported
  2. 21: Supported

Opera Mini

  1. all: Not supported

Opera Mobile

  1. 10 - 11.5: Not supported
  2. 12: Support unknown
  3. 12.1: Supported
  4. 73: Supported

UC Browser for Android

  1. 13.4: Supported

Android Browser

  1. 2.1 - 4.3: Not supported
  2. 4.4 - 4.4.4: Supported
  3. 113: Supported

Firefox for Android

  1. 113: Supported

QQ Browser

  1. 13.1: Supported

Baidu Browser

  1. 13.18: Supported

KaiOS Browser

  1. 2.5: Supported
  2. 3: Supported
Resources:
WebKit feature request bug
MDN Web Docs - getModifierState