ARIA Attributes Must Conform to Valid Values

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Quick Reference

Element Code: AC-018

Issue: ARIA attributes have invalid values

Impact: Invalid values are ignored, breaking intended accessibility features

Fix: Use only valid values as specified in the ARIA specification

Detection: axe DevTools, HTML validators

What Is This Issue?

ARIA attributes accept specific values. For example, aria-expanded accepts only "true" or "false", not "yes", "no", or "1". Invalid values are ignored, making the attribute useless.

Why This Matters for Your Website

Invalid ARIA values provide no accessibility benefit while cluttering your code. Screen readers simply ignore attributes with unrecognized values.

How to Fix This Issue

  1. Check values: Verify against ARIA specification
  2. Use boolean correctly: "true"/"false" strings, not JavaScript booleans
  3. Use valid tokens: For enumerated attributes like aria-live

Tools for Detection

  • axe DevTools: Reports invalid ARIA values
  • HTML Validator: Catches some value errors

TL;DR (The Simple Version)

Your ARIA attributes have invalid values. Check the ARIA spec for allowed values. For example, aria-expanded must be "true" or "false", not "yes" or "1".

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