Gamepad button type attribute

at a glance

why it exists

The Gamepad API defines standard indices for 17 common buttons (the Standard Gamepad mapping), but controllers ship with many more inputs — trackpads, share/capture buttons, voice-assistant buttons, home buttons, squeeze buttons. Today, recognizing them means hardcoding per-controller button-index tables: a DualSense trackpad click is button 17 on that controller, with no interoperable signal. The motivating case is the clickable trackpad on PlayStation controllers (DualShock 4, DualSense): cloud-gaming services want to prompt “press the touchpad” without maintaining a controller database.

The explainer lists the use classes: cloud-gaming services showing controller-specific prompts, browser games adapting UI to controller capabilities, accessibility software describing inputs meaningfully, and any application identifying touchpad input on DualShock/DualSense devices. Explicit non-goals: exposing controller model identifiers, manufacturer information, vendor-specific button names, changing existing mapping behavior, or adding remapping functionality.

how it works

The spec PR adds a §14.1 “Additional gamepad buttons” concept: an extended gamepad button mapping beyond the Standard Gamepad mapping, covering buttons commonly found on certain models — trackpads/touchpads, share or capture buttons, voice-assistant buttons, home buttons, squeeze buttons. The section is explicit that the list is not exhaustive and that user agents may expose different or additional buttons, so a Gamepad's buttons array is not limited to 17 entries.

Every button is then classified by the new attribute relative to that extended mapping:

The classification model deliberately distinguishes "trackpad" (known cross-device semantics) from "non-standard" (controller-specific, no standardized type). The explainer frames the three values as a starting set: future classifications would require separate specification review and Working Group consensus. The full member contract — exposure, lifecycle, edge cases — is on the GamepadButton.type member page.

syntax

The spec PR's WebIDL — a new enum plus a new attribute on the existing GamepadButton interface:

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

[Exposed=Window]
interface GamepadButton {
  readonly attribute boolean pressed;
  readonly attribute boolean touched;
  readonly attribute double value;
  readonly attribute GamepadButtonType type;
};

Chromium's shipped IDL (gamepad_button.idl, fetched 2026-07-29) matches the enum and attribute exactly, annotated with the runtime gate — and its inline comments gloss the values: non-standard = “a button outside the Standard Gamepad layout with no known semantic role”, standard = “a button in the Standard Gamepad layout”, trackpad = “a clickable trackpad surface”:

[RuntimeEnabled=GamepadButtonTypes]
readonly attribute GamepadButtonType type;

examples

Feature detection first — the attribute is absent where unsupported, so prototype detection is clean (pattern from the explainer):

if ("type" in GamepadButton.prototype) {
  // GamepadButton.type is available
}

Finding a trackpad button across connected gamepads (adapted from the explainer's trackpad example):

const gamepad = navigator.getGamepads()[0];
for (const button of gamepad.buttons) {
  if (button.type === "trackpad") {
    console.log("Trackpad button detected");
  }
}

Splitting a controller's buttons by classification:

const standard = gamepad.buttons.filter(b => b.type === "standard");
const extras   = gamepad.buttons.filter(b => b.type === "non-standard");
// e.g. render a standard-layout diagram for `standard`,
// and an "additional controls" section for `extras`

No live showcase demo yet: the Chrome Platform Showcase feature route returned 404 at HEAD-check time (2026-07-29), so per the gendn fallback rule this page links instead of embedding. A live demo also needs real gamepad hardware — this API cannot be exercised with synthetic input.

web platform tests

No dedicated upstream WPT coverage exists for this attribute (2026-07-29): the wpt/gamepad directory lists 16 files — permissions-policy, events, rumble, timestamp, and an idlharness-manual.html — with no button-type test, and spec PR #196 leaves its “Modified Web platform tests” checkbox unticked. The Gamepad API's reliance on physical devices means much of its WPT surface is manual-only.

browser compatibility

Interim table. There is no BCD entry for the type member — BCD api/GamepadButton.json records only pressed, touched, and value (fetched 2026-07-29) — and no web-features entry (a webstatus.dev query returns zero matches). Rows below are compiled from the linked primary sources, not from BCD.

security and privacy

• Read-only, no new capabilities — the attribute is a classification of an input the page can already observe through button indices and state; it adds no device access and requires no permission beyond the existing Gamepad API model (explainer: “No additional permissions are required”).
• Fingerprinting surface — the base spec's §14.2 (PR preview — fingerprinting mitigation) notes that inspecting Gamepad capabilities enables active fingerprinting and permits the user agent to alter exposed device information (for example, clamping button counts to the standard layout) — a mitigation that directly changes which type values a page can observe. The explainer assesses the added surface as minimal: no device, product, or manufacturer identifiers and nothing user-specific beyond what button behavior already reveals.
• Permissions Policy — the Gamepad API defines the policy-controlled feature "gamepad" (default allowlist *); where a document's policy disables it, getGamepads() and gamepadconnected/gamepaddisconnected are blocked, so no GamepadButton objects (and no type values) are reachable at all (PR preview §20; WPT permissions-policy-gamepad.html).
• Backward compatible — support detection is "type" in GamepadButton.prototype; existing content is unaffected (explainer compatibility section).

specifications

see also

• GamepadButton.type — member reference (this site)
• Chrome Platform Status — Gamepad button type attribute (API record)
• blink-dev — Intent to Prototype: Gamepad button type attribute
• Chromium CL 7760763 — prototype (merged, flagged) · Chromium issue 339841686
• WebKit PR #65693 · WebKit bug 266293
• MDN — GamepadButton (the host interface; MDN does not document type — the member URL 404s and search returns no matching document, 2026-07-29) · MDN — Gamepad API
• Chrome Platform Showcase — feature page (demo pending; 404 at check time)