Accessibilitymediumaria
Include required ARIA attributes for roles
rule · aria-required-attr
ARIA roles often have mandatory attributes that must be present for the element to be considered valid and accessible.
Code Example
HTML
<!-- Correct Slider implementation -->
<div role="slider"
aria-valuenow="50"
aria-valuemin="0"
aria-valuemax="100"
aria-label="Volume level">
</div>
<!-- Correct Scrollbar implementation -->
<div role="scrollbar"
aria-controls="content-id"
aria-orientation="vertical"
aria-valuenow="25"
aria-valuemin="0"
aria-valuemax="100">
</div>Why It Matters
- Functional Integrity: Many roles are non-functional without their supporting attributes.
- Accurate Communication: Screen readers rely on these attributes to announce the current state (e.g., the current value of a slider).
- Spec Compliance: Adheres to the W3C ARIA standard, ensuring better cross-browser accessibility.
- User Control: Allows users to understand the boundaries (min/max) and current state of interactive controls.
Exceptions
- Prefer native HTML semantics over ARIA when both are possible; some apparent ARIA failures disappear when the underlying element is corrected.
- A missing ARIA attribute is not automatically the strongest finding if the control is already semantically broken, unnamed, or keyboard-inaccessible.
- Do not add ARIA only to satisfy the rule if the feature should instead be implemented with a native element or a simpler interaction pattern.
Standards
- Align the implementation with WAI-ARIA 1.2 and verify the rendered experience, not only the source code.
- Align the implementation with MDN: ARIA and verify the rendered experience, not only the source code.
Verification
Automated Checks
- Inspect the browser accessibility tree or accessibility pane for the relevant element, role, or accessible name.
- Run an automated accessibility checker such as axe or Lighthouse where applicable.
Manual Checks
- Test the affected UI with keyboard-only navigation and confirm the rule holds in the rendered experience.
- Re-test one representative user flow with a screen reader if this rule affects a key interaction.