ARIA: button role

The button role identifies an element as a button to assistive technology such as screen readers. A button is a widget used to perform actions such as submitting a form, opening a dialog, canceling an action, or performing a command such as inserting a new record or displaying information. Adding role="button" tells assistive technology that the element is a button but provides no button functionality. Use <button> or <input> with type="button" instead.

This button role can be used in combination with the aria-pressed attribute to create toggle buttons.

<div id="saveChanges" tabindex="0" role="button" aria-pressed="false">Save</div>

The above example creates a focusable button, but requires JavaScript and CSS to include button appearance and functionality. These are features provided by default when using the <button> and <input> with type="button" elements:

<button type="button" id="saveChanges">Save</button>

In addition to the ordinary button widget, role="button" should be included when creating a toggle button or menu button using a non-button element.

A toggle button is a two-state button that can be either off (not pressed) or on (pressed). The aria-pressed attribute values of true or false identify a button as a toggle button.

A menu button is a button that controls a menu and has an aria-haspopup property attribute set to either menu or true.

There are some types of user interface components that, when represented in a platform accessibility API, can only contain text. Accessibility APIs do not have a way of representing semantic elements contained in a button. To deal with this limitation, browsers, automatically apply role presentation to all descendant elements of any button element as it is a role that does not support semantic children.

For example, consider the following button element, which contains a heading.

<div role="button"><h3>Title of my button</h3></div>

Because descendants of button are presentational, the following code is equivalent:

<div role="button"><h3 role="presentation">Title of my button</h3></div>

From the assistive technology user's perspective, the heading does not exist since the previous code snippets are equivalent to the following in the accessibility tree:

<div role="button">Title of my button</div>

aria-pressed

The aria-pressed attribute defines the button as a toggle button. The value describes the state of the button. The values include aria-pressed="false" when a button is not currently pressed, aria-pressed="true" to indicate a button is currently pressed, and aria-pressed="mixed" if the button is considered to be partially pressed. If the attribute is omitted or set to its default value of aria-pressed="undefined", the element does not support being pressed.

aria-expanded

If the button controls a grouping of other elements, the aria-expanded state indicates whether the controlled grouping is currently expanded or collapsed. If the button has aria-expanded="false" set, the grouping is not currently expanded; If the button has aria-expanded="true" set, it is currently expanded; if the button has aria-expanded="undefined" set or the attribute is omitted, it is not expandable.

Buttons should always have an accessible name. For most buttons, this name will be the same as the text inside the button, between the opening and closing tags. In some cases, for example buttons represented by icons, the accessible name may be provided from the aria-label or aria-labelledby attributes.

A toggle button typically has two states: pressed and not pressed. A third mixed state is available for toggle buttons that control other elements, such as other toggle buttons or checkboxes, which do not all share the same value. Whether an element is a toggle button or not can be indicated with the aria-pressed attribute in addition to the button role (if the element is not already a native button element):

• If aria-pressed is not used, or is set to the "undefined" state, the button is not a toggle button.
• If aria-pressed="false" is used the button is a toggle button that is currently not pressed.
• If aria-pressed="true" is used the button is a toggle button that is currently pressed.
• if aria-pressed="mixed" is used, the button is considered to be partially pressed.

As an example, the mute button on an audio player labeled "mute" could indicate that sound is muted by setting the aria-pressed state true. The label of a toggle button should not change when its state changes. In our example the label remains "Mute" with a screen reader reading "Mute toggle button pressed" or "Mute toggle button not pressed" depending on the value of aria-pressed. If the design were to call for the button label to change from "Mute" to "Unmute," a toggle button would not be appropriate, so the aria-pressed attribute would be omitted.

Following button activation, focus is set depending on the type of action the button performs. For example, if clicking the button opens a dialog, the focus should move to the dialog. If the button closes a dialog, focus should return to the button that opened the dialog unless the function performed in the dialog context logically leads to a different element. If the button alters the current context, such as muting and unmuting an audio file, then focus typically remains on the button.

Required event handlers

Buttons can be operated by mouse, touch, and keyboard users. For native HTML <button> elements, the button's onclick event fires for mouse clicks and when the user presses Space or Enter while the button has focus. But if another tag is used to create a button, the onclick event only fires when clicked by the mouse cursor, even if role="button" is used. Because of this, separate key event handlers must be added to the element so that the button is be triggered when the Space or Enter key is pressed.

onclick

Handles the event raised when the button is activated using a mouse click or touch event.

onKeyDown

Handles the event raised when the button is activated using the Enter or Space key on the keyboard. (Note not the deprecated onKeyPress)

In this example, a span element has been given the button role. Because a <span> element is used, the tabindex attribute is required to make the button focusable and part of the page's tab order. The included CSS style is provided to make the <span> element look like a button, and to provide visual cues when the button has focus.

The handleBtnClick and handleBtnKeyDown event handlers perform the button's action when activated using a mouse click or the Space or Enter key. In this case, the action is to add a new name to the list of names.

Try the example by adding a name to the text box. The button will cause the name to be added to a list.

HTML

<h1>ARIA Button Example</h1>
<ul id="nameList"></ul>
<label for="newName">Enter your Name: </label>
<input type="text" id="newName" />
<span
  role="button"
  tabindex="0"
  onclick="handleCommand(event)"
  onKeyDown="handleCommand(event)"
  >Add Name</span
>

CSS

[role="button"] {
  padding: 2px;
  background-color: navy;
  color: white;
  cursor: default;
}
[role="button"]:hover,
[role="button"]:focus,
[role="button"]:active {
  background-color: white;
  color: navy;
}
ul {
  list-style: none;
}

JavaScript

function handleCommand(event) {
  // Handles both mouse clicks and keyboard
  // activate with Enter or Space

  // Keypresses other then Enter and Space should not trigger a command
  if (
    event instanceof KeyboardEvent &&
    event.key !== "Enter" &&
    event.key !== " "
  ) {
    return;
  }

  // Get the new name value from the input element
  const newNameInput = document.getElementById("newName");
  const name = newNameInput.value;
  newNameInput.value = ""; // clear the text field
  newNameInput.focus(); // give the text field focus to enable entering and additional name.

  // Don't add blank entries to the list.
  if (name.length > 0) {
    const listItem = document.createElement("li");
    listItem.appendChild(document.createTextNode(name));

    // Add the new name to the list.
    const list = document.getElementById("nameList");
    list.appendChild(listItem);
  }
}

In this snippet a <span> element is converted to a toggle button using the button role and the aria-pressed attribute. When the button is activated, the aria-pressed value switches states; changing from true to false and back again.

HTML

<button
  type="button"
  onclick="handleBtnClick(event)"
  onKeyDown="handleBtnKeyDown(event)">
  Mute Audio
</button>

<span
  role="button"
  tabindex="0"
  aria-pressed="false"
  onclick="handleBtnClick(event)"
  onKeyDown="handleBtnKeyDown(event)">
  Mute Audio
</span>

<audio
  id="audio"
  src="https://soundbible.com/mp3/Tyrannosaurus%20Rex%20Roar-SoundBible.com-807702404.mp3">
  Your browser does not support the `audio` element.
</audio>

CSS

button,
[role="button"] {
  padding: 3px;
  border: 2px solid transparent;
}

button:active,
button:focus,
[role="button"][aria-pressed="true"] {
  border: 2px solid #000;
}

JavaScript

function handleBtnClick(event) {
  toggleButton(event.target);
}

function handleBtnKeyDown(event) {
  // Check to see if space or enter were pressed
  // "Spacebar" for IE11 support
  if (event.key === " " || event.key === "Enter" || event.key === "Spacebar") {
    // Prevent the default action to stop scrolling when space is pressed
    event.preventDefault();
    toggleButton(event.target);
  }
}

function toggleButton(element) {
  const audio = document.getElementById("audio");

  // Check to see if the button is pressed
  const pressed = element.getAttribute("aria-pressed") === "true";

  // Change aria-pressed to the opposite state
  element.setAttribute("aria-pressed", !pressed);

  // Toggle the play state of the audio file
  if (pressed) {
    audio.pause();
  } else {
    audio.play();
  }
}

Result

Buttons are interactive controls and thus focusable. If the button role is added to an element that is not focusable by itself (such as <span>, <div> or <p>) then, the tabindex attribute has to be used to make the button focusable.

When the button role is used, screen readers announce the element as a button, generally saying "click" followed by the button's accessible name. The accessible name is either the content of the element or the value of an aria-label or element referenced by an aria-labelledby attribute, or description, if included.

If a link performs the action of a button, giving the element role="button" helps assistive technology users understand the function of the element. However, a better solution is to adjust the visual design so it matches the function and ARIA role. Where possible, it is recommended to use native HTML buttons (<button>, <input type="button">, <input type="submit">, <input type="reset"> and <input type="image">) rather than the button role, as native HTML buttons are supported by all user agents and assistive technology and provide keyboard and focus requirements by default, without need for additional customization.

• The <button> element
• The <input> element
• <input type="button">
• <input type="submit">
• <input type="reset">
• aria-pressed
• aria-expanded
• aria-haspopup
• Strong native semantics in HTML5
• Notes on Using ARIA in HTML
• Official WAI-ARIA example code