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3.2.7 WAI-ARIA

Authors may use the ARIA role and aria-* attributes on HTML elements, in accordance with the requirements described in the ARIA specifications, except where these conflict with the strong native semantics described below. These exceptions are intended to prevent authors from making assistive technology products report nonsensical states that do not represent the actual state of the document. [ARIA]

User agents are required to implement ARIA semantics on all HTML elements, as defined in the ARIA specifications. The implicit ARIA semantics defined below must be recognized by implementations for the purposes of ARIA processing. [ARIAIMPL]

The ARIA attributes defined in the ARIA specifications, and the strong native semantics and default implicit ARIA semantics defined below, do not have any effect on CSS pseudo-class matching, user interface modalities that don't use assistive technologies, or the default actions of user interaction events as described in this specification.

The following table defines the strong native semantics and corresponding default implicit ARIA semantics that apply to HTML elements. Each language feature (element or attribute) in a cell in the first column implies the ARIA semantics (role, states, and/or properties) given in the cell in the second column of the same row. When multiple rows apply to an element, the role from the last row to define a role must be applied, and the states and properties from all the rows must be combined.

Language feature Strong native semantics and default implied ARIA semantics
area element that creates a hyperlink link role
base element No role
datalist element listbox role, with the aria-multiselectable property set to "false"
details element aria-expanded state set to "true" if the element's open attribute is present, and set to "false" otherwise
dialog element without an open attribute The aria-hidden state set to "true"
head element No role
hgroup element heading role, with the aria-level property set to the element's outline depth
hr element separator role
html element No role
img element whose alt attribute's value is empty presentation role
input element with a type attribute in the Checkbox state aria-checked state set to "mixed" if the element's indeterminate IDL attribute is true, or "true" if the element's checkedness is true, or "false" otherwise
input element with a type attribute in the Color state No role
input element with a type attribute in the Date state No role, with the aria-readonly property set to "true" if the element has a readonly attribute
input element with a type attribute in the Date and Time state No role, with the aria-readonly property set to "true" if the element has a readonly attribute
input element with a type attribute in the Local Date and Time state No role, with the aria-readonly property set to "true" if the element has a readonly attribute
input element with a type attribute in the E-mail state with no suggestions source element textbox role, with the aria-readonly property set to "true" if the element has a readonly attribute
input element with a type attribute in the File Upload state No role
input element with a type attribute in the Hidden state No role
input element with a type attribute in the Month state No role, with the aria-readonly property set to "true" if the element has a readonly attribute
input element with a type attribute in the Number state spinbutton role, with the aria-readonly property set to "true" if the element has a readonly attribute, the aria-valuemax property set to the element's maximum, the aria-valuemin property set to the element's minimum, and, if the result of applying the rules for parsing floating point number values to the element's value is a number, with the aria-valuenow property set to that number
input element with a type attribute in the Password state textbox role, with the aria-readonly property set to "true" if the element has a readonly attribute
input element with a type attribute in the Radio Button state aria-checked state set to "true" if the element's checkedness is true, or "false" otherwise
input element with a type attribute in the Range state slider role, with the aria-valuemax property set to the element's maximum, the aria-valuemin property set to the element's minimum, and the aria-valuenow property set to the result of applying the rules for parsing floating point number values to the element's value, if that results in a number, or the default value otherwise
input element with a type attribute in the Reset Button state button role
input element with a type attribute in the Search state with no suggestions source element textbox role, with the aria-readonly property set to "true" if the element has a readonly attribute
input element with a type attribute in the Submit Button state button role
input element with a type attribute in the Telephone state with no suggestions source element textbox role, with the aria-readonly property set to "true" if the element has a readonly attribute
input element with a type attribute in the Text state with no suggestions source element textbox role, with the aria-readonly property set to "true" if the element has a readonly attribute
input element with a type attribute in the Text, Search, Telephone, URL, or E-mail states with a suggestions source element combobox role, with the aria-owns property set to the same value as the list attribute, and the aria-readonly property set to "true" if the element has a readonly attribute
input element with a type attribute in the Time state No role, with the aria-readonly property set to "true" if the element has a readonly attribute
input element with a type attribute in the URL state with no suggestions source element textbox role, with the aria-readonly property set to "true" if the element has a readonly attribute
input element with a type attribute in the Week state No role, with the aria-readonly property set to "true" if the element has a readonly attribute
input element that is required The aria-required state set to "true"
keygen element No role
label element No role
link element that creates a hyperlink link role
menu element with a type attribute in the context menu state No role
menu element with a type attribute in the list state menu role
menu element with a type attribute in the toolbar state toolbar role
meta element No role
meter element No role
nav element navigation role
noscript element No role
optgroup element No role
option element that is in a list of options or that represents a suggestion in a datalist element option role, with the aria-selected state set to "true" if the element's selectedness is true, or "false" otherwise.
param element No role
progress element progressbar role, with, if the progress bar is determinate, the aria-valuemax property set to the maximum value of the progress bar, the aria-valuemin property set to zero, and the aria-valuenow property set to the current value of the progress bar
script element No role
select element with a multiple attribute listbox role, with the aria-multiselectable property set to "true"
select element with no multiple attribute listbox role, with the aria-multiselectable property set to "false"
select element with a required attribute The aria-required state set to "true"
source element No role
style element No role
summary element No role
textarea element textbox role, with the aria-multiline property set to "true", and the aria-readonly property set to "true" if the element has a readonly attribute
textarea element with a required attribute The aria-required state set to "true"
title element No role
An element that defines a command, whose Type facet is "checkbox", and that is a descendant of a menu element whose type attribute in the list state menuitemcheckbox role, with the aria-checked state set to "true" if the command's Checked State facet is true, and "false" otherwise
An element that defines a command, whose Type facet is "command", and that is a descendant of a menu element whose type attribute in the list state menuitem role
An element that defines a command, whose Type facet is "radio", and that is a descendant of a menu element whose type attribute in the list state menuitemradio role, with the aria-checked state set to "true" if the command's Checked State facet is true, and "false" otherwise
Element that is disabled The aria-disabled state set to "true"
Element that is inert The aria-disabled state set to "true"
Element with a hidden attribute The aria-hidden state set to "true"
Element that is a candidate for constraint validation but that does not satisfy its constraints The aria-invalid state set to "true"

Some HTML elements have native semantics that can be overridden. The following table lists these elements and their default implicit ARIA semantics, along with the restrictions that apply to those elements. Each language feature (element or attribute) in a cell in the first column implies, unless otherwise overridden, the ARIA semantic (role, state, or property) given in the cell in the second column of the same row, but this semantic may be overridden under the conditions listed in the cell in the third column of that row. In addition, any element may be given the presentation role, regardless of the restrictions below.

Language feature Default implied ARIA semantic Restrictions
a element that creates a hyperlink link role Role must be either link, button, checkbox, menuitem, menuitemcheckbox, menuitemradio, tab, or treeitem
address element No role If specified, role must be contentinfo
article element article role Role must be either article, document, application, or main
aside element note role Role must be either note, complementary, or search
audio element No role If specified, role must be application
button element button role Role must be either button, link, menuitem, menuitemcheckbox, menuitemradio, radio
details element group role Role must be a role that supports aria-expanded
dialog element dialog role Role must be either alert, alertdialog, application, contentinfo, dialog, document, log, main, marquee, region, search, or status
embed element No role If specified, role must be either application, document, or img
footer element No role If specified, role must be contentinfo
h1 element that does not have an hgroup ancestor heading role, with the aria-level property set to the element's outline depth Role must be either heading or tab
h2 element that does not have an hgroup ancestor heading role, with the aria-level property set to the element's outline depth Role must be either heading or tab
h3 element that does not have an hgroup ancestor heading role, with the aria-level property set to the element's outline depth Role must be either heading or tab
h4 element that does not have an hgroup ancestor heading role, with the aria-level property set to the element's outline depth Role must be either heading or tab
h5 element that does not have an hgroup ancestor heading role, with the aria-level property set to the element's outline depth Role must be either heading or tab
h6 element that does not have an hgroup ancestor heading role, with the aria-level property set to the element's outline depth Role must be either heading or tab
header element No role If specified, role must be banner
iframe element No role If specified, role must be either application, document, or img
img element whose alt attribute's value is absent img role No restrictions
img element whose alt attribute's value is present and not empty img role No restrictions
input element with a type attribute in the Button state button role Role must be either button, link, menuitem, menuitemcheckbox, menuitemradio, radio
input element with a type attribute in the Checkbox state checkbox role Role must be either checkbox or menuitemcheckbox
input element with a type attribute in the Image Button state button role Role must be either button, link, menuitem, menuitemcheckbox, menuitemradio, radio
input element with a type attribute in the Radio Button state radio role Role must be either radio or menuitemradio
li element whose parent is an ol or ul element listitem role Role must be either listitem, menuitemcheckbox, menuitemradio, option, tab, or treeitem
object element No role If specified, role must be either application, document, or img
ol element list role Role must be either directory, list, listbox, menu, menubar, tablist, toolbar, tree
output element status role No restrictions
section element region role Role must be either alert, alertdialog, application, contentinfo, dialog, document, log, main, marquee, region, search, or status
ul element list role Role must be either directory, list, listbox, menu, menubar, tablist, toolbar, tree
video element No role If specified, role must be application
The body element document role Role must be either document or application

The entry "no role", when used as a strong native semantic, means that no role other than presentation can be used. When used as a default implied ARIA semantic, it means the user agent has no default mapping to ARIA roles. (However, it probably will have its own mappings to the accessibility layer.)

The WAI-ARIA specification neither requires or forbids user agents from enhancing native presentation and interaction behaviors on the basis of WAI- ARIA markup. Even mainstream user agents might choose to expose metadata or navigational features directly or via user-installed extensions; for example, exposing required form fields or landmark navigation. User agents are encouraged to maximize their usefulness to users, including users without disabilities.

Conformance checkers are encouraged to phrase errors such that authors are encouraged to use more appropriate elements rather than remove accessibility annotations. For example, if an a element is marked as having the button role, a conformance checker could say "Use a more appropriate element to represent a button, for example a button element or an input element" rather than "The button role cannot be used with a elements".

These features can be used to make accessibility tools render content to their users in more useful ways. For example, ASCII art, which is really an image, appears to be text, and in the absence of appropriate annotations would end up being rendered by screen readers as a very painful reading of lots of punctuation. Using the features described in this section, one can instead make the ATs skip the ASCII art and just read the caption:

<figure role="img" aria-labelledby="fish-caption"> 
 <pre>
 o           .'`/
     '      /  (
   O    .-'` ` `'-._      .')
      _/ (o)        '.  .' /
      )       )))     ><  <
      `\  |_\      _.'  '. \
        '-._  _ .-'       '.)
    jgs     `\__\
 </pre>
 <figcaption id="fish-caption">
  Joan G. Stark, "<cite>fish</cite>".
  October 1997. ASCII on electrons. 28×8.
 </figcaption> 
</figure>