<button>: The Button element

This element's attributes include the global attributes.

autofocus

This Boolean attribute specifies that the button should have input focus when the page loads. Only one element in a document can have this attribute.

command

Specifies the action to be performed on an element being controlled by a control <button>, specified via the commandfor attribute. The possible values are:

"show-modal"

The button will show a <dialog> as modal. If the dialog is already modal, no action will be taken.

"close"

The button will close a <dialog> element. If the dialog is already closed, no action will be taken.

"show-popover"

The button will show a hidden popover. If you try to show an already showing popover, no action will be taken. See Popover API for more details.

"hide-popover"

The button will hide a showing popover. If you try to hide an already hidden popover, no action will be taken. See Popover API for more details.

"toggle-popover"

The button will toggle a popover between showing and hidden. If the popover is hidden, it will be shown; if the popover is showing, it will be hidden. See Popover API for more details.

Custom values

This attribute can represent custom values that are prefixed with a two hyphen characters (--). Buttons with a custom value will dispatch the CommandEvent on the controlled element.

commandfor

Turns a <button> element into a button, controlling the given interactive element; takes the ID of the element to control as its value.

disabled

This Boolean attribute prevents the user from interacting with the button: it cannot be pressed or focused.

form

The <form> element to associate the button with (its form owner). The value of this attribute must be the id of a <form> in the same document. (If this attribute is not set, the <button> is associated with its ancestor <form> element, if any.)

This attribute lets you associate <button> elements to <form>s anywhere in the document, not just inside a <form>. It can also override an ancestor <form> element.

formaction

The URL that processes the information submitted by the button. Overrides the action attribute of the button's form owner. Does nothing if there is no form owner.

formenctype

If the button is a submit button (it's inside/associated with a <form> and doesn't have type="button"), specifies how to encode the form data that is submitted. Possible values:

• application/x-www-form-urlencoded: The default if the attribute is not used.
• multipart/form-data: Used to submit <input> elements with their type attributes set to file.
• text/plain: Specified as a debugging aid; shouldn't be used for real form submission.

If this attribute is specified, it overrides the enctype attribute of the button's form owner.

formmethod

If the button is a submit button (it's inside/associated with a <form> and doesn't have type="button"), this attribute specifies the HTTP method used to submit the form. Possible values:

• post: The data from the form are included in the body of the HTTP request when sent to the server. Use when the form contains information that shouldn't be public, like login credentials.
• get: The form data are appended to the form's action URL, with a ? as a separator, and the resulting URL is sent to the server. Use this method when the form has no side effects, like search forms.
• dialog: This method is used to indicate that the button closes the dialog with which it is associated, and does not transmit the form data at all.

If specified, this attribute overrides the method attribute of the button's form owner.

formnovalidate

If the button is a submit button, this Boolean attribute specifies that the form is not to be validated when it is submitted. If this attribute is specified, it overrides the novalidate attribute of the button's form owner.

This attribute is also available on <input type="image"> and <input type="submit"> elements.

formtarget

If the button is a submit button, this attribute is an author-defined name or standardized, underscore-prefixed keyword indicating where to display the response from submitting the form. This is the name of, or keyword for, a browsing context (a tab, window, or <iframe>). If this attribute is specified, it overrides the target attribute of the button's form owner. The following keywords have special meanings:

• _self: Load the response into the same browsing context as the current one. This is the default if the attribute is not specified.
• _blank: Load the response into a new unnamed browsing context — usually a new tab or window, depending on the user's browser settings.
• _parent: Load the response into the parent browsing context of the current one. If there is no parent, this option behaves the same way as _self.
• _top: Load the response into the top-level browsing context (that is, the browsing context that is an ancestor of the current one, and has no parent). If there is no parent, this option behaves the same way as _self.

name

The name of the button, submitted as a pair with the button's value as part of the form data, when that button is used to submit the form.

popovertarget

Turns a <button> element into a popover control button; takes the ID of the popover element to control as its value. See the Popover API landing page for more details.

popovertargetaction

Specifies the action to be performed on a popover element being controlled by a control <button>. Possible values are:

"hide"

The button will hide a shown popover. If you try to hide an already hidden popover, no action will be taken.

"show"

The button will show a hidden popover. If you try to show an already showing popover, no action will be taken.

"toggle"

The button will toggle a popover between showing and hidden. If the popover is hidden, it will be shown; if the popover is showing, it will be hidden. If popovertargetaction is omitted, "toggle" is the default action that will be performed by the control button.

type

The default behavior of the button. Possible values are:

• submit: The button submits the form data to the server. This is the default if the attribute is not specified for buttons associated with a <form>, or if the attribute is an empty or invalid value.
• reset: The button resets all the controls to their initial values, like <input type="reset">. (This behavior tends to annoy users.)
• button: The button has no default behavior, and does nothing when pressed by default. It can have client-side scripts listen to the element's events, which are triggered when the events occur.

value

Defines the value associated with the button's name when it's submitted with the form data. This value is passed to the server in params when the form is submitted using this button.

A submit button with the attribute formaction set, but without an associated form does nothing. You have to set a form owner, either by wrapping it in a <form> or set the attribute form to the id of the form.

<button> elements are much easier to style than <input> elements. You can add inner HTML content (think <i>, <br>, or even <img>), and use ::after and ::before pseudo-elements for complex rendering.

If your buttons are not for submitting form data to a server, be sure to set their type attribute to button. Otherwise, they will try to submit form data and to load the (nonexistent) response, possibly destroying the current state of the document.

While <button type="button"> has no default behavior, event handlers can be scripted to trigger behaviors. An activated button can perform programmable actions using JavaScript, such as removing an item from a list.

By default, user agents style buttons as display: flow-root, which establishes a new block formatting context and centers the button's children both horizontally and vertically as long as they do not overflow. If the button is defined as a flex or grid container, the children will behave as flex or grid items. A button set to display: inline will be styled as if the value were set to display: inline-block.

Buttons that only display an icon do not have an accessible name. Accessible names provide information for assistive technology, such as screen readers, to access when they parse the document and generate an accessibility tree. Assistive technology then uses the accessibility tree to navigate and manipulate page content.

To give an icon button an accessible name, put text in the <button> element that concisely describes the button's functionality.

Examples

<button name="favorite">
  <svg fill="#000000" viewBox="0 0 42 42">
    <path
      d="M21,1c1.081,0,5.141,12.315,6.201,13.126s13.461,1.053,13.791,2.137 c0.34,1.087-9.561,8.938-9.961,10.252c-0.409,1.307,
      3.202,13.769,2.331,14.442c-0.879,0.673-11.05-6.79-12.361-6.79 c-1.311,0-11.481,7.463-12.36,6.79c-0.871-0.674,2.739-13.136,
      2.329-14.442c-0.399-1.313-10.3-9.165-9.96-10.252 c0.33-1.084,12.731-1.326,13.791-2.137S19.91,1,21,1z"></path>
  </svg>
  Add to favorites
</button>

Result

If you want to visually hide the button's text, an accessible way to do so is to use a combination of CSS properties to remove it visually from the screen, but keep it parsable by assistive technology.

However, it is worth noting that leaving the button text visible can help people who may not be familiar with the icon's meaning or understand the button's purpose. This is especially important for people who are not technologically sophisticated or who may have different cultural interpretations of the icon the button uses.

• What is an accessible name? | The Paciello Group
• MDN Understanding WCAG, Guideline 4.1 explanations
• Understanding Success Criterion 4.1.2 | W3C Understanding WCAG 2.0

Size

Interactive elements such as buttons should have an area large enough to be easy to activate. This helps a variety of people, including people with motor control issues and people using non-precise forms of input such as a stylus or fingers. A minimum interactive size of 44×44 CSS pixels is recommended.

• Understanding Success Criterion 2.5.5: Target Size | W3C Understanding WCAG 2.1
• Target Size and 2.5.5 | Adrian Roselli
• Quick test: Large touch targets - The A11Y Project

Proximity

Large amounts of interactive content — including buttons — placed in close visual proximity to each other should have space separating them. This spacing is beneficial for people who are experiencing motor control issues, who may accidentally activate the wrong interactive content.

Spacing may be created using CSS properties such as margin.

• Hand tremors and the giant-button-problem - Axess Lab

To describe the state of a button the correct ARIA attribute to use is aria-pressed and not aria-checked or aria-selected. To find out more read the information about the ARIA button role.

It is best not to override the default focus ring for elements that have focus. If the button styles are overridden, it is important to ensure that the focus state has enough contrast so that people experiencing low vision conditions can perceive it and people with cognitive differences will understand it.

The :focus-visible pseudo-class can be used to apply styles to an element that has :focus only when the user agent's heuristics determine that the focus should be highlighted, such as when a <button> receives keyboard focus. See :focus vs :focus-visible for more information.

Color contrast ratio is determined by comparing the luminosity of the button text and background color values to the background the button is placed on. To meet current Web Content Accessibility Guidelines (WCAG), a ratio of 4.5:1 is required for text content and 3:1 for large text. (Large text is defined as 18.66px and bold or larger, or 24px or larger.)

• WebAIM: Color Contrast Checker
• MDN Understanding WCAG, Guideline 1.4 explanations
• Understanding Success Criterion 1.4.3 | W3C Understanding WCAG 2.0

Whether clicking on a <button> or <input> button types causes it to (by default) become focused varies by browser and OS. Most browsers do give focus to a button being clicked, but Safari does not, by design.