Element: keyup event

The keyup event is fired when a key is released.

The keydown and keyup events provide a code indicating which key is pressed, while keypress indicates which character was entered. For example, a lowercase "a" will be reported as 65 by keydown and keyup, but as 97 by keypress. An uppercase "A" is reported as 65 by all events.

Since Firefox 65, the keyup and keydown events are now fired during IME composition, to improve cross-browser compatibility for CJKT users (bug 354358. To ignore all keyup events that are part of composition, do something like this (229 is a special value set for a keyCode relating to an event that has been processed by an IME):

eventTarget.addEventListener("keyup", event => {
  if (event.isComposing || event.keyCode === 229) {
    return;
  }
  // do something
});

This example logs the KeyboardEvent.code value whenever you release a key inside the <input> element.

<input placeholder="Click here, then press and release a key." size="40">
<p id="log"></p>

const input = document.querySelector('input');
const log = document.getElementById('log');

input.addEventListener('keyup', logKey);

function logKey(e) {
  log.textContent += `${e.code}`;
}

• input
• keydown
• keypress
• Document keyup event