User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:30.0) Gecko/20100101 Firefox/30.0 (Beta/Release) Build ID: 20140605174243 Steps to reproduce: 1: Change keyboard layout to Katakana or Hiragana 2: Set listener for keyUp, keyDown, or keyPress events Actual results: Events do not register until the enter key is pressed. Expected results: Events should register per key press.

Could you attach a minimum testcase?

Switch your keyboard Katakana or Hiragana, try the interactive demo here, http://www.willmaster.com/library/tutorials/onkeydown-onkeyup-onclick-and-onchange-javascript-events.php

Ah, I see what you say, probably. This must be a dup of bug 354358. FYI: keydown/keyup events are fired on other browsers even during using IME. However, it would be INVALID in DOM Level 3 Events definition.