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
- Check values: Verify against ARIA specification
- Use boolean correctly: "true"/"false" strings, not JavaScript booleans
- 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".
Claude Vincent is a technical SEO consultant focused on crawlability, rendering, and AI-search visibility. He writes the field guides and case studies at SEO ProCheck, with a bias toward the durable, unglamorous work that decides whether search engines and AI answer engines can actually read and cite a site.
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