KeyboardEvent.code

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

KeyboardEvent.code属性表示键盘上的物理键（与按键生成的字符相对）。换句话说，此属性返回一个值，该值不会被键盘布局或修饰键的状态改变。

如果输入设备不是物理键盘，而是虚拟键盘或辅助功能设备，则浏览器将设置返回值，以尽可能地匹配物理键盘所发生的情况，从而最大限度地提高物理和虚拟输入设备之间的兼容性。

当你想要根据输入设备上的物理位置处理键而不是与这些键相关联的字符时，此属性非常有用;这在编写代码来处理游戏输入时尤为常见，这些游戏使用键盘上的键来模拟类似游戏板的环境。但请注意，你无法使用 KeyboardEvent.code报告的值来确定击键生成的字符，因为键码的名称可能与按键上打印的实际字符或按下键时计算机生成的字符不匹配。

例如，QWERTY 布局键盘上的“q”键返回的code是“KeyQ”，但 Dvorak 键盘上的“'”键和 AZERTY 键盘上的“a”键也返回的相同code值。这使得如果用户没有使用预期的键盘布局，则无法使用code值来确定用户按键的名称。

要确定哪个字符与键事件对应，请改用KeyboardEvent.key属性。

示例

练习 KeyboardEvent

HTML

html
<p>
  Press keys on the keyboard to see what the KeyboardEvent's key and code values
  are for each one.
</p>
<div id="output"></div>

CSS

css
#output {
  font-family: Arial, Helvetica, sans-serif;
  border: 1px solid black;
}

JavaScript

js
window.addEventListener(
  "keydown",
  function (event) {
    let str =
      "KeyboardEvent: key='" + event.key + "' | code='" + event.code + "'";
    let el = document.createElement("span");
    el.innerHTML = str + "<br/>";

    document.getElementById("output").appendChild(el);
  },
  true,
);

Try it out

To ensure that keystrokes go to the sample, click in the output box below before pressing keys.

Handle keyboard events in a game

This example establishes an event listener for keydown events which handles keyboard input for a game which uses the typical "WASD" keyboard layout for steering forward, left, backward, and right. This will use the same four keys physically regardless of what the actual corresponding characters are, such as if the user is using an AZERTY keyboard.

HTML

html
<p>Use the WASD (ZQSD on AZERTY) keys to move and steer.</p>
<svg xmlns="http://www.w3.org/2000/svg" version="1.1" class="world">
  <polygon id="spaceship" points="15,0 0,30 30,30" />
</svg>
<script>
  refresh();
</script>

CSS

css
.world {
  margin: 0px;
  padding: 0px;
  background-color: black;
  width: 400px;
  height: 400px;
}

#spaceship {
  fill: orange;
  stroke: red;
  stroke-width: 2px;
}

JavaScript

The first section of the JavaScript code establishes some variables we'll be using. shipSize contains the size of the ship the player is moving around, for convenience. position is used to track the position of the ship within the play field. moveRate and turnRate are the number of pixels forward and backward each keystroke moves the ship and how many degrees of rotation the left and right steering controls apply per keystroke. angle is the current amount of rotation applied to the ship, in degrees; it starts at 0° (pointing straight up). Finally, spaceship is set to refer to the element with the ID "spaceship", which is the SVG polygon representing the ship the player controls.

js
let shipSize = {
  width: 30,
  height: 30,
};

let position = {
  x: 200,
  y: 200,
};

let moveRate = 9;
let turnRate = 5;

let angle = 0;

let spaceship = document.getElementById("spaceship");

Next comes the function updatePosition(). This function takes as input the distance the ship is to be moved, where positive is a forward movement and negative is a backward movement. This function computes the new position of the ship given the distance moved and the current direction the ship is facing. It also handles ensuring that the ship wraps across the boundaries of the play field instead of vanishing.

js
function updatePosition(offset) {
  let rad = angle * (Math.PI / 180);
  position.x += Math.sin(rad) * offset;
  position.y -= Math.cos(rad) * offset;

  if (position.x < 0) {
    position.x = 399;
  } else if (position.x > 399) {
    position.x = 0;
  }

  if (position.y < 0) {
    position.y = 399;
  } else if (position.y > 399) {
    position.y = 0;
  }
}

The refresh() function handles applying the rotation and position by using an SVG transform.

js
function refresh() {
  let x = position.x - shipSize.width / 2;
  let y = position.y - shipSize.height / 2;
  let transform = "translate(" + x + " " + y + ") rotate(" + angle + " 15 15) ";

  spaceship.setAttribute("transform", transform);
}

Finally, the addEventListener() method is used to start listening for keydown events, acting on each key by updating the ship position and rotation angle, then calling refresh() to draw the ship at its new position and angle.

js
window.addEventListener(
  "keydown",
  function (event) {
    if (event.preventDefaulted) {
      return; // Do nothing if event already handled
    }

    switch (event.code) {
      case "KeyS":
      case "ArrowDown":
        // Handle "back"
        updatePosition(-moveRate);
        break;
      case "KeyW":
      case "ArrowUp":
        // Handle "forward"
        updatePosition(moveRate);
        break;
      case "KeyA":
      case "ArrowLeft":
        // Handle "turn left"
        angle -= turnRate;
        break;
      case "KeyD":
      case "ArrowRight":
        // Handle "turn right"
        angle += turnRate;
        break;
    }

    refresh();

    // Consume the event so it doesn't get handled twice
    event.preventDefault();
  },
  true,
);

Try it out

To ensure that keystrokes go to the sample code, click inside the black game play field below before pressing keys.

There are several ways this code can be made better. Most real games would watch for keydown events, start motion when that happens, and stop the motion when the corresponding keyup occurs, instead of relying on key repeats. That would allow both smoother and faster movement, but would also allow the player to be moving and steering at the same time. Transitions or animations could be used to make the ship's movement smoother, too.

Specification

Specification
UI Events
# dom-keyboardevent-code

Browser compatibility

BCD tables only load in the browser

Code values

The following tables show what code values are used for each native scancode or virtual keycode on major platforms. Because some browsers choose to interpret physical keys differently, there are some differences in which keys map to which codes. These tables show those variations when known.

Code values on Windows

This table shows the Windows scan codes representing keys and the KeyboardEvent.code values which correspond to those hardware keys. Only keys which generate scan codes on Windows are listed.

KeyboardEvent.code value
Code Firefox Chrome
0x0000

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0x0001 "Escape" "Escape"
0x0002 "Digit0" "Digit0"
0x0003 "Digit1" "Digit1"
0x0004 "Digit2" "Digit2"
0x0005 "Digit3" "Digit3"
0x0006 "Digit4" "Digit4"
0x0007 "Digit5" "Digit5"
0x0008 "Digit6" "Digit6"
0x0009 "Digit7" "Digit7"
0x000A "Digit8" "Digit8"
0x000B "Digit9" "Digit9"
0x000C "Minus" "Minus"
0x000D "Equal" "Equal"
0x000E "Backspace" "Backspace"
0x000F "Tab" "Tab"
0x0010 "KeyQ" "KeyQ"
0x0011 "KeyW" "KeyW"
0x0012 "KeyE" "KeyE"
0x0013 "KeyR" "KeyR"
0x0014 "KeyT" "KeyT"
0x0015 "KeyY" "KeyY"
0x0016 "KeyU" "KeyU"
0x0017 "KeyI" "KeyI"
0x0018 "KeyO" "KeyO"
0x0019 "KeyP" "KeyP"
0x001A "BracketLeft" "BracketLeft"
0x001B "BracketRight" "BracketRight"
0x001C "Enter" "Enter"
0x001D "ControlLeft" "ControlLeft"
0x001E "KeyA" "KeyA"
0x001F "KeyS" "KeyS"
0x0020 "KeyD" "KeyD"
0x0021 "KeyF" "KeyF"
0x0022 "KeyG" "KeyG"
0x0023 "KeyH" "KeyH"
0x0024 "KeyJ" "KeyJ"
0x0025 "KeyK" "KeyK"
0x0026 "KeyL" "KeyL"
0x0027 "Semicolon" "Semicolon"
0x0028 "Quote" "Quote"
0x0029 "Backquote" "Backquote"
0x002A "ShiftLeft" "ShiftLeft"
0x002B "Backslash" "Backslash"
0x002C "KeyZ" "KeyZ"
0x002D "KeyX" "KeyX"
0x002E "KeyC" "KeyC"
0x002F "KeyV" "KeyV"
0x0030 "KeyB" "KeyB"
0x0031 "KeyN" "KeyN"
0x0032 "KeyM" "KeyM"
0x0033 "Comma" "Comma"
0x0034 "Period" "Period"
0x0035 "Slash" "Slash"
0x0036 "ShiftRight" "ShiftRight"
0x0037 "NumpadMultiply" "NumpadMultiply"
0x0038 "AltLeft" "AltLeft"
0x0039 "Space" "Space"
0x003A "CapsLock" "CapsLock"
0x003B "F1" "F1"
0x003C "F2" "F2"
0x003D "F3" "F3"
0x003E "F4" "F4"
0x003F "F5" "F5"
0x0040 "F6" "F6"
0x0041 "F7" "F7"
0x0042 "F8" "F8"
0x0043 "F9" "F9"
0x0044 "F10" "F10"
0x0045 "Pause" "Pause"
0x0046 "ScrollLock" "ScrollLock"
0x0047 "Numpad7" "Numpad7"
0x0048 "Numpad8" "Numpad8"
0x0049 "Numpad9" "Numpad9"
0x004A "NumpadSubtract" "NumpadSubtract"
0x004B "Numpad4" "Numpad4"
0x004C "Numpad5" "Numpad5"
0x004D "Numpad6" "Numpad6"
0x004E "NumpadAdd" "NumpadAdd"
0x004F "Numpad1" "Numpad1"
0x0050 "Numpad2" "Numpad2"
0x0051 "Numpad3" "Numpad3"
0x0052 "Numpad0" "Numpad0"
0x0053 "NumpadDecimal" "NumpadDecimal"
0x0054 (Alt + PrintScreen) "PrintScreen" ""
0x0055

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0x0056 "IntlBackslash" "IntlBackslash"
0x0057 "F11" "F11"
0x0058 "F12" "F12"
0x0059 "NumpadEqual" ""
0x005A

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0x005B

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

"F13"
0x005C

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

"F14"
0x005D

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

"F15"
0x005E

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0x005F

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0x0060

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0x0061

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0x0062

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0x0063

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

"F16"
0x0064 "F13" "F17"
0x0065 "F14" "F18"
0x0066 "F15" "F19"
0x0067 "F16" "F20"
0x0068 "F17" "F21"
0x0069 "F18" "F22"
0x006A "F19" "F23"
0x006B "F20" "F24"
0x006C "F21" ""
0x006D "F22" ""
0x006E "F23" ""
0x006F

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0x0070 "KanaMode" ""
0x0071 (Hanja key without Korean keyboard layout) "Lang2" ""
0x0072 (Han/Yeong key without Korean keyboard layout) "Lang1" ""
0x0073 "IntlRo" ""
0x0074, 0x0075

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0x0076 "F24" ""
0x0077, 0x0078

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0x0079 "Convert" ""
0x007A

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0x007B "NonConvert" ""
0x007C

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0x007D "IntlYen" "IntlYen"
0x007E "NumpadComma" ""
0x007F

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0xE000 ～ 0xE007

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0xE008

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

"Undo"
0xE009

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0xE00A "" "Paste"
0xE00B ～ 0xE00F "" ""
0xE010 "MediaTrackPrevious" "MediaTrackPrevious"
0xE011 ～ 0xE016 "" ""
0xE017

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

"Cut"
0xE018

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

"Copy"
0xE019 "MediaTrackNext" "MediaTrackNext"
0xE01A, 0xE01B

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0xE01C "NumpadEnter" "NumpadEnter"
0xE01D "ControlRight" "ControlRight"
0xE01E

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

"LaunchMail"
0xE01F

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0xE020 "AudioVolumeMute" (was "VolumeMute" until Firefox 49) "AudioVolumeMute" (was "VolumeMute" until Chrome 50)
0xE021 "LaunchApp2" ""
0xE022 "MediaPlayPause" "MediaPlayPause"
0xE023

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0xE024 "MediaStop" "MediaStop"
0xE025 ～ 0xE02B

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0xE02C

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

"Eject"
0xE02D

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0xE02E

"AudioVolumeDown"

Prior to Firefox 48, this key code is reported as "VolumeDown".

"VolumeDown" (was "VolumeDown" until Chrome 50)
0xE02F

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0xE030

"AudioVolumeUp"

Prior to Firefox 48, this key code is reported as "VolumeUp".

"VolumeUp" (was "VolumeUp" until Chrome 50)
0xE031

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0xE032 "BrowserHome" "BrowserHome"
0xE033, 0xE034

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0xE035 "NumpadDivide" "NumpadDivide"
0xE036

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0xE037 "PrintScreen" "PrintScreen"
0xE038 "AltRight" "AltRight"
0xE039, 0xE03A

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0xE03B

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

"Help"
0xE03C～ 0xE044

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0xE045 "NumLock" "NumLock"
0xE046 (Ctrl + Pause) "Pause" "Pause"
0xE047 "Home" "Home"
0xE048 "ArrowUp" "ArrowUp"
0xE049 "PageUp" "PageUp"
0xE04A

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0xE04B "ArrowLeft" "ArrowLeft"
0xE04C

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0xE04D "ArrowRight" "ArrowRight"
0xE04E

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0xE04F "End" "End"
0xE050 "ArrowDown" "ArrowDown"
0xE051 "PageDown" "PageDown"
0xE052 "Insert" "Insert"
0xE053 "Delete" "Delete"
0xE054 ～ 0xE05A

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0xE05B

"MetaLeft"

Prior to Firefox 48, this key code was reported as "OSLeft".

"OSLeft"
0xE05C

"MetaRight"

Prior to Firefox 48, this key code was reported as "OSRight".

"OSRight"
0xE05D "ContextMenu" "ContextMenu"
0xE05E "Power" ""
0xE05F ～ 0xE064

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0xE065 "BrowserSearch" "BrowserSearch"
0xE066 "BrowserFavorites" "BrowserFavorites"
0xE067 "BrowserRefresh" "BrowserRefresh"
0xE068 "BrowserStop" "BrowserStop"
0xE069 "BrowserForward" "BrowserForward"
0xE06A "BrowserBack" "BrowserBack"
0xE06B "LaunchApp1" ""
0xE06C "LaunchMail" ""
0xE06D "LaunchMediaPlayer" ("MediaSelect" prior to Firefox 49) ""
0xE06E ～ 0xE0F0

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0xE0F1 (Hanja key with Korean keyboard layout) "Lang2" ""
0xE0F2 (Han/Yeong key with Korean keyboard layout) "Lang1" ""

Code values on Mac

On Mac OS X, it's hard to get scancode or something which can distinguish a physical key from a key event. Therefore, Gecko always maps code value from the virtual keycode.

Virtual keycode Gecko (32) Chromium (48)
kVK_ANSI_A (0x00) "KeyA" "KeyA"
kVK_ANSI_S (0x01) "KeyS" "KeyS"
kVK_ANSI_D (0x02) "KeyD" "KeyD"
kVK_ANSI_F (0x03) "KeyF" "KeyF"
kVK_ANSI_H (0x04) "KeyH" "KeyH"
kVK_ANSI_G (0x05) "KeyG" "KeyG"
kVK_ANSI_Z (0x06) "KeyZ" "KeyZ"
kVK_ANSI_X (0x07) "KeyX" "KeyX"
kVK_ANSI_C (0x08) "KeyC" "KeyC"
kVK_ANSI_V (0x09) "KeyV" "KeyV"
kVK_ISO_Section (0x0A) "IntlBackslash" "IntlBackslash"
kVK_ANSI_B (0x0B) "KeyB" "KeyB"
kVK_ANSI_Q (0x0C) "KeyQ" "KeyQ"
kVK_ANSI_W (0x0D) "KeyW" "KeyW"
kVK_ANSI_E (0x0E) "KeyE" "KeyE"
kVK_ANSI_R (0x0F) "KeyR" "KeyR"
kVK_ANSI_Y (0x10) "KeyY" "KeyY"
kVK_ANSI_T (0x11) "KeyT" "KeyT"
kVK_ANSI_1 (0x12) "Digit1" "Digit1"
kVK_ANSI_2 (0x13) "Digit2" "Digit2"
kVK_ANSI_3 (0x14) "Digit3" "Digit3"
kVK_ANSI_4 (0x15) "Digit4" "Digit4"
kVK_ANSI_6 (0x16) "Digit6" "Digit6"
kVK_ANSI_5 (0x17) "Digit7" "Digit7"
kVK_ANSI_Equal (0x18) "Equal" "Equal"
kVK_ANSI_9 (0x19) "Digit9" "Digit9"
kVK_ANSI_7 (0x1A) "Digit7" "Digit7"
kVK_ANSI_Minus (0x1B) "Minus" "Minus"
kVK_ANSI_8 (0x1C) "Digit8" "Digit8"
kVK_ANSI_0 (0x1D) "Digit0" "Digit0"
kVK_ANSI_RightBracket (0x1E) "BracketRight" "BracketRight"
kVK_ANSI_O (0x1F) "KeyO" "KeyO"
kVK_ANSI_U (0x20) "KeyU" "KeyU"
kVK_ANSI_LeftBracket (0x21) "BracketLeft" "BracketLeft"
kVK_ANSI_I (0x22) "KeyI" "KeyI"
kVK_ANSI_P (0x23) "KeyP" "KeyP"
kVK_Return (0x24) "Enter" "Enter"
kVK_ANSI_L (0x25) "KeyL" "KeyL"
kVK_ANSI_J (0x26) "KeyJ" "KeyJ"
kVK_ANSI_Quote (0x27) "Quote" "Quote"
kVK_ANSI_K (0x28) "KeyK" "KeyK"
kVK_ANSI_Semicolon (0x29) "Semicolon" "Semicolon"
kVK_Tab (0x30) "Tab" "Tab"
kVK_Space (0x31) "Space" "Space"
kVK_ANSI_Grave (0x32) "Backquote" "Backquote"
kVK_Delete (0x33) "Backspace" "Backspace"
Enter key on keypad of PowerBook (0x34) "NumpadEnter" ""
kVK_Escape (0x35) "Escape" "Escape"
right-command key (0x36) "OSRight" "OSRight"
kVK_Command (0x37) "OSLeft" "OSLeft"
kVK_Shift (0x38) "ShiftLeft" "ShiftLeft"
kVK_CapsLock (0x39) "CapsLock" "CapsLock"
kVK_Option (0x3A) "AltLeft" "AltLeft"
kVK_Control (0x3B) "ControlLeft" "ControlLeft"
kVK_RightShift (0x3C) "ShiftRight" "ShiftRight"
kVK_RightOption (0x3D) "AltRight" "AltRight"
kVK_RightControl (0x3E) "ControlRight" "ControlRight"
kVK_Function (0x3F) "Fn" (no events fired actually) "" (no events fired actually)
kVK_F17 (0x40) "F17" "F17"
kVK_ANSI_KeypadDecimal (0x41) "NumpadDecimal" "NumpadDecimal"
kVK_ANSI_KeypadMultiply (0x43) "NumpadMultiply" "NumpadMultiply"
kVK_ANSI_KeypadPlus (0x45) "NumpadAdd" "NumpadAdd"
kVK_ANSI_KeypadClear (0x47) "NumLock" "NumLock"
kVK_VolumeUp (0x48) "AudioVolumeUp" (was "VolumeUp" until Firefox 48) "AudioVolumeUp" (was "VolumeUp" until Chrome 50)
kVK_VolumeDown (0x49) "AudioVolumeDown" (was "VolumeDown" until Firefox 49) "AudioVolumeDown" (was "VolumeDown" until Chrome 50)
kVK_Mute (0x4A) "AudioVolumeMute" (was "VolumeMute" until Firefox 49) "AudioVolumeMute" (was "VolumeMute" until Chrome 50)
kVK_ANSI_KeypadDivide (0x4B) "NumpadDivide" "NumpadDivide"
kVK_ANSI_KeypadEnter (0x4C) "NumpadEnter" "NumpadEnter"
kVK_ANSI_KeypadMinus (0x4E) "NumpadSubtract" "NumpadSubtract"
kVK_F18 (0x4F) "F18" "F18"
kVK_F19 (0x50) "F19" "F19"
kVK_ANSI_KeypadEquals (0x51) "NumpadEqual" "NumpadEqual"
kVK_ANSI_Keypad0 (0x52) "Numpad0" "Numpad0"
kVK_ANSI_Keypad1 (0x53) "Numpad1" "Numpad1"
kVK_ANSI_Keypad2 (0x54) "Numpad2" "Numpad2"
kVK_ANSI_Keypad3 (0x55) "Numpad3" "Numpad3"
kVK_ANSI_Keypad4 (0x56) "Numpad4" "Numpad4"
kVK_ANSI_Keypad5 (0x57) "Numpad5" "Numpad5"
kVK_ANSI_Keypad6 (0x58) "Numpad6" "Numpad6"
kVK_ANSI_Keypad7 (0x59) "Numpad7" "Numpad7"
kVK_F20 (0x5A) "F20" "F20"
kVK_ANSI_Keypad8 (0x5B) "Numpad8" "Numpad8"
kVK_ANSI_Keypad9 (0x5C) "Numpad9" "Numpad9"
kVK_JIS_Yen (0x5D) "IntlYen" "IntlYen"
kVK_JIS_Underscore (0x5E) "IntlRo" "IntlRo"
kVK_JIS_KeypadComma (0x5F) "NumpadComma" "NumpadComma"
kVK_F5 (0x60) "F5" "F5"
kVK_F6 (0x61) "F6" "F6"
kVK_F7 (0x62) "F7" "F7"
kVK_F3 (0x63) "F3" "F3"
kVK_F8 (0x64) "F8" "F8"
kVK_F9 (0x65) "F9" "F9"
kVK_JIS_Eisu (0x66)

"Lang2"

Prior to Firefox 37, this key incorrectly generated the key code "RomanCharacters".

"" (no events fired actually)
kVK_F11 (0x67) "F11" "F11"
kVK_JIS_Kana (0x68) "Lang1" "KanaMode" (no events fired actually)
kVK_F13 (0x69) "F13" "F13"
kVK_F16 (0x6A) "F16" "F16"
kVK_F14 (0x6B) "F14" "F14"
kVK_F10 (0x6D) "F10" "F10"
kVK_F12 (0x6F) "F12" "F12"
kVK_F15 (0x71) "F15" "F15"
kVK_Help (0x72) "Help" "Insert"
kVK_Home (0x73) "Home" "Home"
kVK_PageUp (0x74) "PageUp" "PageUp"
kVK_ForwardDelete (0x75) "Delete" "Delete"
kVK_F4 (0x76) "F4" "F4"
kVK_End (0x77) "End" "End"
kVK_F2 (0x78) "F2" "F2"
kVK_PageDown (0x79) "PageDown" "PageDown"
kVK_F1 (0x7A) "F1" "F1"
kVK_LeftArrow (0x7B) "ArrowLeft" "ArrowLeft"
kVK_RightArrow (0x7C) "ArrowRight" "ArrowRight"
kVK_DownArrow (0x7D) "ArrowDown" "ArrowDown"
kVK_UpArrow (0x7E) "ArrowUp" "ArrowUp"

Code values on Linux (X11) (When scancode is available)

Note that X has too many keys and some of them are not testable with usual keyboard. So, following table is created from source code which maps from scancode to code value.

scancode (hardware_keycode) Gecko (32) Chromium (44)
0x0009 "Escape" "Escape"
0x000A "Digit1" "Digit1"
0x000B "Digit2" "Digit2"
0x000C "Digit3" "Digit3"
0x000D "Digit4" "Digit4"
0x000E "Digit5" "Digit5"
0x000F "Digit6" "Digit6"
0x0010 "Digit7" "Digit7"
0x0011 "Digit8" "Digit8"
0x0012 "Digit9" "Digit9"
0x0013 "Digit0" "Digit0"
0x0014 "Minus" "Minus"
0x0015 "Equal" "Equal"
0x0016 "Backspace" "Backspace"
0x0017 "Tab" "Tab"
0x0018 "KeyQ" "KeyQ"
0x0019 "KeyW" "KeyW"
0x001A "KeyE" "KeyE"
0x001B "KeyR" "KeyR"
0x001C "KeyT" "KeyT"
0x001D "KeyY" "KeyY"
0x001E "KeyU" "KeyU"
0x001F "KeyI" "KeyI"
0x0020 "KeyO" "KeyO"
0x0021 "KeyP" "KeyP"
0x0022 "BracketLeft" "BracketLeft"
0x0023 "BracketRight" "BracketRight"
0x0024 "Enter" "Enter"
0x0025 "ControlLeft" "ControlLeft"
0x0026 "KeyA" "KeyA"
0x0027 "KeyS" "KeyS"
0x0028 "KeyD" "KeyD"
0x0029 "KeyF" "KeyF"
0x002A "KeyG" "KeyG"
0x002B "KeyH" "KeyH"
0x002C "KeyJ" "KeyJ"
0x002D "KeyK" "KeyK"
0x002E "KeyL" "KeyL"
0x002F "Semicolon" "Semicolon"
0x0030 "Quote" "Quote"
0x0031 "Backquote" "Backquote"
0x0032 "ShiftLeft" "ShiftLeft"
0x0033 "Backslash" "Backslash"
0x0034 "KeyZ" "KeyZ"
0x0035 "KeyX" "KeyX"
0x0036 "KeyC" "KeyC"
0x0037 "KeyV" "KeyV"
0x0038 "KeyB" "KeyB"
0x0039 "KeyN" "KeyN"
0x003A "KeyM" "KeyM"
0x003B "Comma" "Comma"
0x003C "Period" "Period"
0x003D "Slash" "Slash"
0x003E "ShiftRight" "ShiftRight"
0x003F "NumpadMultiply" "NumpadMultiply"
0x0040 "AltLeft" "AltLeft"
0x0041 "Space" "Space"
0x0042 "CapsLock" "CapsLock"
0x0043 "F1" "F1"
0x0044 "F2" "F2"
0x0045 "F3" "F3"
0x0046 "F4" "F4"
0x0047 "F5" "F5"
0x0048 "F6" "F6"
0x0049 "F7" "F7"
0x004A "F8" "F8"
0x004B "F9" "F9"
0x004C "F10" "F10"
0x004D "NumLock" "NumLock"
0x004E "ScrollLock" "ScrollLock"
0x004F "Numpad7" "Numpad7"
0x0050 "Numpad8" "Numpad8"
0x0051 "Numpad9" "Numpad9"
0x0052 "NumpadSubtract" "NumpadSubtract"
0x0053 "Numpad4" "Numpad4"
0x0054 "Numpad5" "Numpad5"
0x0055 "Numpad6" "Numpad6"
0x0056 "NumpadAdd" "NumpadAdd"
0x0057 "Numpad1" "Numpad1"
0x0058 "Numpad2" "Numpad2"
0x0059 "Numpad3" "Numpad3"
0x005A "Numpad0" "Numpad0"
0x005B "NumpadDecimal" "NumpadDecimal"
0x005C, 0x005D "Unidentified" ""
0x005E "IntlBackslash" "IntlBackslash"
0x005F "F11" "F11"
0x0060 "F12" "F12"
0x0061 "IntlRo" "IntlRo"
0x0062, 0x0063 "Unidentified" ""
0x0064 "Convert" "Convert"
0x0065 "KanaMode" "KanaMode"
0x0066 "NonConvert" "NonConvert"
0x0067 "Unidentified" ""
0x0068 "NumpadEnter" "NumpadEnter"
0x0069 "ControlRight" "ControlRight"
0x006A "NumpadDivide" "NumpadDivide"
0x006B "PrintScreen" "PrintScreen"
0x006C "AltRight" "AltRight"
0x006D "Unidentified" ""
0x006E "Home" "Home"
0x006F "ArrowUp" "ArrowUp"
0x0070 "PageUp" "PageUp"
0x0071 "ArrowLeft" "ArrowLeft"
0x0072 "ArrowRight" "ArrowRight"
0x0073 "End" "End"
0x0074 "ArrowDown" "ArrowDown"
0x0075 "PageDown" "PageDown"
0x0076 "Insert" "Insert"
0x0077 "Delete" "Delete"
0x0078 "Unidentified" ""
0x0079 "AudioVolumeMute" (was "VolumeMute" until Firefox 49) "AudioVolumeMute" (was "VolumeMute" until Chrome 50)
0x007A "AudioVolumeDown" (was "VolumeDown" until Firefox 49) "AudioVolumeDown" (was "VolumeDown" until Chrome 50)
0x007B "AudioVolumeUp" (was "VolumeUp" until Firefox 49) "AudioVolumeUp" (was "VolumeUp" until Chrome 50)
0x007C "Unidentified" "Power"
0x007D "NumpadEqual" "NumpadEqual"
0x007E "Unidentified" "NumpadChangeSign"
0x007F "Pause" "Pause"
0x0080 "Unidentified" ""
0x0081 "NumpadComma" ""
0x0082 "Lang1" "HangulMode"
0x0083 "Lang2" "Hanja"
0x0084 "IntlYen" "IntlYen"
0x0085 "OSLeft" "OSLeft"
0x0086 "OSRight" "OSRight"
0x0087 "ContextMenu" "ContextMenu"
0x0088 "BrowserStop" "Cancel"
0x0089 "Again" ""
0x008A "Props" ""
0x008B "Undo" "Undo"
0x008C "Select" ""
0x008D "Copy" "Copy"
0x008E "Open" ""
0x008F "Paste" "Paste"
0x0090 "Find" ""
0x0091 "Cut" "Cut"
0x0092 "Help" "Help"
0x0093 "Unidentified" ""
0x0094 "LaunchApp2" ""
0x0095, 0x0096 "Unidentified" ""
0x0097 "WakeUp" ""
0x0098 "LaunchApp1" ""
0x0099 ～ 0x00A2 "Unidentified" ""
0x00A3 "LaunchMail" ""
0x00A4 "BrowserFavorites" ""
0x00A5 "Unidentified" ""
0x00A6 "BrowserBack" "BrowserBack"
0x00A7 "BrowserForward" "BrowserForward"
0x00A8 "Unidentified" ""
0x00A9 "Eject" ""
0x00AA "Unidentified" ""
0x00AB "MediaTrackNext" ""
0x00AC "MediaPlayPause" ""
0x00AD "MediaTrackPrevious" ""
0x00AE "MediaStop" ""
0x00AF ～ 0x00B2 "Unidentified" ""
0x00B3 "LaunchMediaPlayer" ("MediaSelect" prior to Firefox 49) ""
0x00B4 "BrowserHome" ""
0x00B5 "BrowserRefresh" "BrowserRefresh"
0x00B6 ～ 0x00BA "Unidentified" ""
0x00BB

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

"NumpadParenLeft"
0x00BC

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

"NumpadParenRight"
0x00BD, 0x00BE

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0x00BF "F13" ""
0x00C0 "F14" ""
0x00C1 "F15" ""
0x00C2 "F16" ""
0x00C3 "F17" ""
0x00C4 "F18" ""
0x00C5 "F19" ""
0x00C6 "F20" ""
0x00C7 "F21" ""
0x00C8 "F22" ""
0x00C9 "F23" ""
0x00CA "F24" ""
0x00CB ～ 0x00E0

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

""
0x00E1 "BrowserSearch" ""

Code values on Android and Firefox OS (When scancode is available)

scancode Gecko (32)
0x0001 "Escape"
0x0002 "Digit1"
0x0003 "Digit2"
0x0004 "Digit3"
0x0005 "Digit4"
0x0006 "Digit5"
0x0007 "Digit6"
0x0008 "Digit7"
0x0009 "Digit8"
0x000A "Digit9"
0x000B "Digit0"
0x000C "Minus"
0x000D "Equal"
0x000E "Backspace"
0x000F "Tab"
0x0010 "KeyQ"
0x0011 "KeyW"
0x0012 "KeyE"
0x0013 "KeyR"
0x0014 "KeyT"
0x0015 "KeyY"
0x0016 "KeyU"
0x0017 "KeyI"
0x0018 "KeyO"
0x0019 "KeyP"
0x001A "BracketLeft"
0x001B "BracketRight"
0x001C "Enter"
0x001D "ControlLeft"
0x001E "KeyA"
0x001F "KeyS"
0x0020 "KeyD"
0x0021 "KeyF"
0x0022 "KeyG"
0x0023 "KeyH"
0x0024 "KeyJ"
0x0025 "KeyK"
0x0026 "KeyL"
0x0027 "Semicolon"
0x0028 "Quote"
0x0029 "Backquote"
0x002A "ShiftLeft"
0x002B "Backslash"
0x002C "KeyZ"
0x002D "KeyX"
0x002E "KeyC"
0x002F "KeyV"
0x0030 "KeyB"
0x0031 "KeyN"
0x0032 "KeyM"
0x0033 "Comma"
0x0034 "Period"
0x0035 "Slash"
0x0036 "ShiftRight"
0x0037 "NumpadMultiply"
0x0038 "AltLeft"
0x0039 "Space"
0x003A "CapsLock"
0x003B "F1"
0x003C "F2"
0x003D "F3"
0x003E "F4"
0x003F "F5"
0x0040 "F6"
0x0041 "F7"
0x0042 "F8"
0x0043 "F9"
0x0044 "F10"
0x0045 "NumLock"
0x0046 "ScrollLock"
0x0047 "Numpad7"
0x0048 "Numpad8"
0x0049 "Numpad9"
0x004A "NumpadSubtract"
0x004B "Numpad4"
0x004C "Numpad5"
0x004D "Numpad6"
0x004E "NumpadAdd"
0x004F "Numpad1"
0x0050 "Numpad2"
0x0051 "Numpad3"
0x0052 "Numpad0"
0x0053 "NumpadDecimal"
0x0054, 0x0055

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

0x0056 "IntlBackslash"
0x0057 "F11"
0x0058 "F12"
0x0059 "IntlRo"
0x005A, 0x005B

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

0x005C "Convert"
0x005D "KanaMode"
0x005E "NonConvert"
0x005F

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

0x0060 "NumpadEnter"
0x0061 "ControlRight"
0x0062 "NumpadDivide"
0x0063 "PrintScreen"
0x0064 "AltRight"
0x0065

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

0x0066 "Home"
0x0067 "ArrowUp"
0x0068 "PageUp"
0x0069 "ArrowLeft"
0x006A "ArrowRight"
0x006B "End"
0x006C "ArrowDown"
0x006D "PageDown"
0x006E "Insert"
0x006F "Delete"
0x0070

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

0x0071

"AudioVolumeMute"

Prior to Firefox 48, this key code is identifi9ed as "VolumeMute".

0x0072

"AudioVolumeDown"

Prior to Firefox 48, this key code is identifi9ed as "VolumeDown".

0x0073

"AudioVolumeUp"

Prior to Firefox 48, this key code is identifi9ed as "VolumeUp".

0x0074 "Power"
0x0075 "NumpadEqual"
0x0076

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

0x0077 "Pause"
0x0078

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

0x0079 "NumpadComma"
0x007A "Lang1"
0x007B "Lang2"
0x007C "IntlYen"
0x007D

"MetaLeft"

Prior to Firefox 48, this key code is reported as "OSLeft".

0x007E

"MetaRight"

Prior to Firefox 49, this key code is reported as "MetaRight".

0x007F "ContextMenu"
0x0080 "BrowserStop"
0x0081 "Again"
0x0082 "Props"
0x0083 "Undo"
0x0084 "Select"
0x0085 "Copy"
0x0086 "Open"
0x0087 "Paste"
0x0088 "Find"
0x0089 "Cut"
0x008A "Help"
0x008B ～ 0x008D

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

0x008E "Sleep"
0x008F "WakeUp"
0x0090 "LaunchApp1"
0x0091 ～ 0x009B

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

0x009C "BrowserFavorites"
0x009D

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

0x009E "BrowserBack"
0x009F "BrowserForward"
0x00A0

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

0x00A1 "Eject"
0x00A2

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

0x00A3 "MediaTrackNext"
0x00A4 "MediaPlayPause"
0x00A5 "MediaTrackPrevious"
0x00A6 "MediaStop"
0x00A7 ～ 0x00AC

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

0x00AD "BrowserRefresh"
0x00AE ～ 0x00B6 "Unidentified" Prior to Firefox 48, this key code is reported as "" (an empty string).
0x00B7 "F13"
0x00B8 "F14"
0x00B9 "F15"
0x00BA "F16"
0x00BB "F17"
0x00BC "F18"
0x00BD "F19"
0x00BE "F20"
0x00BF "F21"
0x00C0 "F22"
0x00C1 "F23"
0x00C2 "F24"
0x00C3 ～ 0x00D8

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

0x00D9 "BrowserSearch"
0x00DA ～ 0x01CF

"Unidentified"

Prior to Firefox 48, this key code is reported as "" (an empty string).

0x01D0 "Fn"