Element: keydown event

{{APIRef}} 

The keydown event is fired when a key is pressed.

Unlike the deprecated {{domxref("Element/keypress_event", "keypress")}}  event, the keydown event is fired for all keys, regardless of whether they produce a character value.

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.

The event target of a key event is the currently focused element which is processing the keyboard activity. This includes: {{HTMLElement("input")}} , {{HTMLElement("textarea")}} , anything that is contentEditable, and anything else that can be interacted with the keyboard, such as {{HTMLElement("a")}} , {{HTMLElement("button")}} , and {{HTMLElement("summary")}} . If no suitable element is in focus, the event target will be the {{HTMLElement("body")}}  or the root. The event bubbles. It can reach {{domxref("Document")}}  and {{domxref("Window")}} .

The event target might change between different key events. For example, the keydown target for pressing the Tab key would be different from the keyup target, because the focus has changed.

Syntax

Use the event name in methods like {{domxref("EventTarget.addEventListener", "addEventListener()")}} , or set an event handler property.

addEventListener("keydown", (event) => {});

onkeydown = (event) => {};

Event type

A {{domxref("KeyboardEvent")}} . Inherits from {{domxref("UIEvent")}}  and {{domxref("Event")}} .

{{InheritanceDiagram("KeyboardEvent")}} 

Event properties

This interface also inherits properties of its parents, {{domxref("UIEvent")}}  and {{domxref("Event")}} .

• {{domxref("KeyboardEvent.altKey")}}  {{ReadOnlyInline}} 

  • : Returns a boolean value that is true if the Alt (Option or ⌥ on macOS) key was active when the key event was generated.

• {{domxref("KeyboardEvent.code")}}  {{ReadOnlyInline}} 

  • : Returns a string with the code value of the physical key represented by the event.

    [!WARNING] This ignores the user’s keyboard layout, so that if the user presses the key at the “Y” position in a QWERTY keyboard layout (near the middle of the row above the home row), this will always return “KeyY”, even if the user has a QWERTZ keyboard (which would mean the user expects a “Z” and all the other properties would indicate a “Z”) or a Dvorak keyboard layout (where the user would expect an “F”). If you want to display the correct keystrokes to the user, you can use {{domxref("Keyboard.getLayoutMap()")}} .

• {{domxref("KeyboardEvent.ctrlKey")}}  {{ReadOnlyInline}} 

  • : Returns a boolean value that is true if the Ctrl key was active when the key event was generated.

• {{domxref("KeyboardEvent.isComposing")}}  {{ReadOnlyInline}} 

  • : Returns a boolean value that is true if the event is fired between after compositionstart and before compositionend.

• {{domxref("KeyboardEvent.key")}}  {{ReadOnlyInline}} 

  • : Returns a string representing the key value of the key represented by the event.

• {{domxref("KeyboardEvent.location")}}  {{ReadOnlyInline}} 

  • : Returns a number representing the location of the key on the keyboard or other input device. A list of the constants identifying the locations is shown in Keyboard locations.

• {{domxref("KeyboardEvent.metaKey")}}  {{ReadOnlyInline}} 

  • : Returns a boolean value that is true if the Meta key (on Mac keyboards, the ⌘ Command key; on Windows keyboards, the Windows key (⊞)) was active when the key event was generated.

• {{domxref("KeyboardEvent.repeat")}}  {{ReadOnlyInline}} 

  • : Returns a boolean value that is true if the key is being held down such that it is automatically repeating.

• {{domxref("KeyboardEvent.shiftKey")}}  {{ReadOnlyInline}} 

  • : Returns a boolean value that is true if the Shift key was active when the key event was generated.

Examples

addEventListener keydown example

This example logs the {{domxref("KeyboardEvent.code")}}  value whenever you press down a key inside the {{HtmlElement("input")}}  element.

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

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

input.addEventListener("keydown", logKey);

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

{{EmbedLiveSample("addEventListener_keydown_example")}} 

keydown events with IME

Since Firefox 65, the keydown and keyup events are now fired during {{glossary("Input method editor")}}  composition, to improve cross-browser compatibility for CJKT users (Firefox bug 354358). To ignore all keydown 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("keydown", (event) => {
  if (event.isComposing || event.keyCode === 229) {
    return;
  }
  // do something
});

Note: compositionstart may fire after keydown when typing the first character that opens up the IME, and compositionend may fire before keydown when typing the last character that closes the IME. In these cases, isComposing is false even when the event is part of composition. However, {{domxref("KeyboardEvent.keyCode")}}  is still 229 in these cases, so it’s still advisable to check keyCode as well, although it’s deprecated.

Specifications

{{Specifications}} 

Browser compatibility

{{Compat}} 

See also

• input
• keypress
• keyup