GamepadButton.type

syntax

Verbatim WebIDL from the spec PR:

enum GamepadButtonType {
  "non-standard",
  "standard",
  "trackpad",
};

partial interface GamepadButton {
  readonly attribute GamepadButtonType type;
};

Chromium's IDL is identical in substance, with the runtime gate (gamepad_button.idl, fetched 2026-07-29):

[RuntimeEnabled=GamepadButtonTypes]
readonly attribute GamepadButtonType type;

value

A GamepadButtonType string. The enum's three values, with the spec's definitions and Chromium's IDL comments:

The classification is relative to the extended gamepad button mapping introduced alongside the attribute (PR §14.1): buttons in the 17-entry Standard Gamepad layout are "standard"; extended buttons with a known cross-device semantic role get their own value ("trackpad" is the only such role so far); extended buttons with no standardized role are "non-standard". The explainer is explicit that the value set is a starting point: new classifications require separate spec review and Working Group consensus.

The attribute's getter steps, per the PR preview: “An enumerated GamepadButtonType attribute that classifies the current button's type in relation to an extended mapping.”

inputs

None. type is a read-only attribute: it takes no arguments, has no setter, and is not configurable by the page. The value reflects the user agent's device mapping, not any author-supplied input.

errors

No error surface exists for this member. The IDL declares no [Throws] annotation and the attribute is read-only, so the getter has no defined exception path; there are no argument-validation, state, or security errors to handle. Reading type on a browser without the feature is a different situation — the property is then absent, not an error: button.type evaluates to undefined and "type" in GamepadButton.prototype is false (see examples).

context and exposure

• Exposed in Window only — the GamepadButton interface is [Exposed=Window]; the attribute is not available in workers.
• Reachable only through a live gamepad — obtain instances via navigator.getGamepads()[i].buttons[j]; a type value is observable only while a gamepad exposing that button is connected.
• Permissions Policy — the API is gated by the gamepad policy-controlled feature (default allowlist *); where disabled, getGamepads() and the gamepad connection events are blocked, so no GamepadButton objects are reachable (PR preview §20).
• Runtime gate in Chromium — [RuntimeEnabled=GamepadButtonTypes]; without the flag the member is not present on the interface at all.

lifecycle

• Fixed per device mapping — the value is a classification of the physical control's role in the user agent's mapping for that device, not of momentary state. The spec PR defines no mechanism for a button's type to change during a connection, and no event fires for type changes (only the existing gamepadconnected/gamepaddisconnected device events exist).
• Polling model unchanged — like pressed/touched/value, the attribute is read off GamepadButton objects obtained from navigator.getGamepads() inside the usual polling loop; unlike those, the classification does not vary frame to frame.
• UA mitigation may reshape what's visible — under the base spec's fingerprinting mitigation (§14.2), a user agent MAY clamp the exposed button set to the standard layout, in which case extended buttons (and their "non-standard"/"trackpad" values) never appear.

examples

Guard, then classify every button of the first connected gamepad:

if (!("type" in GamepadButton.prototype)) {
  console.log("GamepadButton.type not supported in this browser");
} else {
  const gamepad = navigator.getGamepads()[0];
  gamepad.buttons.forEach((button, index) => {
    console.log(`Button ${index}: type=${button.type}`);
  });
}

Show a touchpad prompt only when the controller actually has one:

const hasTrackpad = gamepad.buttons.some(b => b.type === "trackpad");
if (hasTrackpad) showPrompt("Press the touchpad");

browser compatibility

Interim table — no BCD key for type exists (api/GamepadButton.json has only pressed/touched/value, fetched 2026-07-29). Compiled from primary sources:

security and privacy

• Read-only classification — exposes no device, product, or manufacturer identifiers and nothing not already inferable from button count, indices, and behavior; no new permission is required (explainer security/privacy sections).
• Fingerprinting — the base spec (§14.2) permits the user agent to reduce the exposed capability set to blunt active fingerprinting; the explainer assesses the attribute's added surface as minimal.
• Policy-gated with the rest of the API — inherits the gamepad Permissions-Policy gate; nothing about type bypasses it.

see also

• Gamepad button type attribute — feature overview (this site)
• Chrome Platform Status — Gamepad button type attribute (5075054393163776)
• w3c/gamepad PR #196 preview — GamepadButtonType enum
• MDN — GamepadButton (host interface; does not document type, 2026-07-29)