Axe Core Guide
Frames with focusable content must not have tabindex=-1
tabindex="-1"
cannot be present in <frame>
and <iframe>
elements with focusable content.
The browser is unable to move the focus to the content included in a frame when it has a negative tabindex. This stops keyboard navigation from skipping all of its content, and if the frame is scrollable, it also prevents the focus from moving to any element from which the frame may be scrolled.
What this Accessibility Rule Checks
Examine all frame
and iframe
elements that contain a negative tabindex value, such as tabindex="-1"
. If there are any such frames, make sure they don’t have nested frames that do contain focusable items.
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Related Accessibility Rules
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.
The destination, purpose, function, or action of an ARIA command element must be made clear in understandable text for screen reader users.
The function of items with the roles link
, button
, or menuitem
that lack an accessible name cannot be understood by screen reader users.
What this Accessibility Rule Checks
Verifies that all elements with the roles link
, button
, or menuitem
have a clear, understandable name.
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.
For screen reader users, aria meter elements must have legible language that defines the destination, function, or action.
Users of screen readers are unable to determine the function of items with role="meter"
but no accessible name.
What this Accessibility Rule Checks
Checks that all items with role="meter"
have a distinguishable, accessible name.
For screen reader users, Aria progressbar items must include understandable language that specifies the destination, purpose, or action.
Users of screen readers are unable to determine the purpose of items with the role="progressbar"
attribute that lack an accessible name.
What this Accessibility Rule Checks
Checks that all items with role="progressbar"
have a distinguishable, accessible name.
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.
Screen reader users are required to have access to understandable text within Aria tooltip
elements. This text must define the destination, purpose, function, or action in a clear and concise manner.
Users of screen readers are unable to understand the function of elements that have the role of tooltip
but do not have accessible names.
What this Accessibility Rule Checks
Performs a check on all elements that have the role tooltip
to ensure that they have a name that can be understood and is accessible.