Accessibility Checking for Large Sites

Not all ARIA role-attribute combinations are valid. This rule ensures that each role has the required qualities.

Using ARIA attributes in roles where they are not permitted can impair web page accessibility. Using an improper role-attribute combination will have no effect on application accessibility at best and may trigger behavior that blocks accessibility for entire areas of an application at worst.

When ARIA attributes are used on HTML elements that do not conform to WAI-ARIA 1.1, they interfere with the semantics of the elements, causing assistive technology products to display nonsensical user interface (UI) information that does not represent the document’s true UI.

What this Accessibility Rule Checks

Checks that each element with an ARIA role is using only the ARIA attributes that are permitted for that role.

This rule determines whether or not aria-hidden elements contain focusable elements.

Using the property aria-hidden="true" on an element removes the element and all of its child nodes from the accessibility API, rendering the element fully unavailable to screen readers and other assistive technology.

aria-hidden may be used with extreme discretion to hide visibly displayed content from assistive technologies if the act of hiding this content is meant to enhance the experience of assistive technology users by reducing redundant or superfluous content.

If aria-hidden is employed to hide material from screen readers, the same or equal meaning and functionality must be made available to assistive technologies.

Using aria-hidden="false" on content that is a descendant of an element that is hidden using aria-hidden="true" will not reveal that content to the accessibility API, nor will it be accessible to screen readers or other assistive technology.

The rule applies to any element whose aria-hidden attribute value is true.

By adding aria-hidden="true" to an element, authors assure that assistive technologies will disregard the element. This can be used to hide aesthetic elements, such as icon typefaces, that are not intended to be read by assistive technologies.

A focusable element with aria-hidden="true" is disregarded as part of the reading order, but is still part of the focus order, making it unclear if it is visible or hidden.

What this Accessibility Rule Checks

For all user interface components, including form elements, links, and script-generated components, the name and role can be identified programmatically; user-specified states, properties, and values can be set programmatically; and user agents, including assistive technologies, are notified of changes.

Ensures every ARIA input field has an accessible name.

This rule ensures that each ARIA input field has a name that is accessible.

There must be accessible names for the following input field roles:

• combobox
• listbox
• searchbox
• slider
• spinbutton
• textbox

What this Accessibility Rule Checks

The names of ARIA input fields must be accessible.

Ensures that the aria-roledescription attribute is only applied to elements having explicit or implicit role values.

Inappropriate aria-roledescription attribute values that clash with an element’s implicit or explicit role value can impede the web page’s accessibility. A contradictory aria-roledescription attribute value may have no effect on the application’s accessibility and may trigger behavior that blocks accessibility for entire application sections.

When aria-roledescription attributes are applied to HTML elements not in accordance with WAI-ARIA 1.1, a semantic conflict may occur between the aria-roledescription value and the implicit or explicit element role value, resulting in assistive technology products reporting nonsensical user interface (UI) information that does not accurately represent the intended UI experience.

What this Accessibility Rule Checks

Use aria-roledescription values to adequately explain implicit or explicit element role values.

ARIA role values must be assigned valid values. Role values must be appropriately written, correlate to existing ARIA role values, and not be abstract roles in order to correctly display the element’s purpose.

Assistive technologies do not read elements with erroneous ARIA role values as intended by the developer.

When screen readers and other assistive devices do not know the function of each element on a web page, they are unable to interact with or communicate the function to the user. When a role value is invalid, an element’s characteristics, properties, and ways of transmitting information to and/or from the user can be communicated via assistive technologies.

What this Accessibility Rule Checks

Examines each element containing the WAI-ARIA role property to check that its value is valid.

Makes certain that each ARIA toggle field has an accessible name.

Ensures that any element having a semantic role has a name that is easily accessible.

Among the semantic roles are:

• checkbox
• menu
• menuitemcheckbox
• menuitemradio
• radio
• radiogroup
• switch

What this Accessibility Rule Checks

There is an accessible name for ARIA toggle fields.

Valid values must be present for ARIA properties that begin with aria-.

To fulfill the intended accessibility purpose, these values must be written correctly and relate to values that make sense for a certain property.

ARIA attributes (those beginning with aria-) must have legitimate values. For a given attribute to fulfill the intended accessibility function, these values must be written correctly and correlate to values that make sense.

A diverse range of values are accepted for many ARIA attributes. There must be permitted values, acceptable “undefined” values, and acceptable “default” values.

Content that does not adhere to the permitted values is inaccessible to users of assistive technology.

What this Accessibility Rule Checks

Verifies that the WAI-ARIA attributes’ values are correct for each element that contains them.

To be valid, definition list items (dt and / or dd) must be enclosed by parent dl elements. This allows screen reader users to recognize the right hierarchy of the list’s information.

A definition list item is invalid if it is not surrounded by parent dl elements.

A definition list must adhere to a particular hierarchy. Using the dl element, a list is defined. It is followed by alternating sets of dt and dd elements, beginning with dt. dt elements define a term while dd elements denote a term’s description. Each group of dt components must be accompanied by a group of dd elements. In the definition list, only dt and dd items are permitted. If not followed, this hierarchy will render the list invalid.

What this Accessibility Rule Checks

Ensures that every child dd and dt element has a parent dl element.

The title element of the HTML document must not be empty in order to give users with an overview of its content.

Users using screen readers utilize page titles to obtain an overview of the page’s content. If a page lacks a title, navigating through it can soon become difficult and confusing for screen reader users. The title element of the page is the first item screen reader users hear when the page loads.

When they arrive at a page, screen reader users hear the page’s title first. If there is no title or if the title is not descriptive and unique, users of screen readers must read the page to discern its content and purpose.

What this Accessibility Rule Checks

Makes certain that each HTML document has a title tag associated with it.

To help screen reader users understand the contents of each frame or iframe element in the document, each element must have a distinct title.

A frame title is used by screen reader users to describe the contents of the frame. If the frames are not identified with a title element, navigating across frames and iframes can soon become challenging and confusing for users of this technology.

Users of screen readers can choose to display a list of all the titles for the frames on a page. Users can locate the frame they’re looking for more quickly by adding descriptive, distinctive labels. Without titles, moving between frames can become challenging and perplexing very quickly. Screen readers will instead provide information such as “frame,” “javascript,” the filename, or the URL if there is no title specified. This information won’t usually be particularly useful.

What this Accessibility Rule Checks

Make sure that the title attribute on every iframe and frame element is distinct and not empty.