People in their early stages of their accessibility journey are often confused about the Web Content Accessibility Guidelines (WCAG) Conformance levels and what the expectations are to meet them. Here’s a quick glimpse into their meaning and how you should approach them.

WCAG Conformance Level A

WCAG Level A is the minimum accessibility standard, ensuring basic access to essential features for users with disabilities.

To achieve Level A, a website must:

  • Satisfy all Level A success criteria (e.g., providing text alternatives for images, keyboard accessibility, avoiding content that flashes).
  • Or, provide a conforming alternate version of the content that meets these criteria.

Level A addresses major barriers for:

  • Screen reader users
  • Keyboard-only users
  • Users with seizures or cognitive challenges

Example Requirements at Level A:

  • Images must have alt text
  • Videos must have captions if they contain audio
  • Content must be navigable by keyboard
  • Avoid flashing content that could trigger seizures

Level A provides a basic foundation for accessibility, but it’s not sufficient on its own to ensure broad access. Most organizations strive for Level AA, which builds on Level A with additional improvements.

WCAG Conformance Level AA

WCAG Level AA is the mid-level standard in the Web Content Accessibility Guidelines, expanding on Level A with additional criteria to better support users with visual, auditory, motor, and cognitive disabilities.

To meet Level AA, a digital product must:

Level AA is the most commonly targeted standard for legal compliance (such as under the ADA, Section 508, or EN 301 549 in Europe).

Level AA provides enhanced accessibility for:

  • People with low vision or color blindness
  • Users who need clear navigation and structure
  • Users who need captions and audio descriptions

Example Requirements at Level AA:

  • Color contrast must be at least 4.5:1 between text and background.
  • Captions are required for live video content.
  • Resizable text must remain readable and functional up to 200%.
  • Headings and labels must be clear and descriptive.
  • Navigation should be consistent across pages.
  • Status messages must be programmatically conveyed to assistive technologies.

WCAG Conformance Level AAA

WCAG Level AAA is the highest accessibility standard, adding enhanced criteria to Levels A and AA to support users with more severe or multiple disabilities.

To meet Level AAA, a website must:

Note: Level AAA is not required for most websites and is often not practical to achieve for all content types.

Level AAA helps users with:

  • Severe visual or hearing impairments
  • Cognitive and learning disabilities
  • Neurological or speech disabilities

Example Requirements at Level AAA:

  • Sign language interpretation must be provided for all prerecorded videos with speech.
  • Extended audio descriptions must be available when there’s not enough pause time in a video.
  • Color contrast must be at least 7:1 between text and background.
  • Reading level must not exceed lower secondary education (unless necessary).
  • Users must be able to re-authenticate without losing data (e.g., in forms).
  • Content must not rely on sensory characteristics alone (like color or shape).

Important Notes

  • Level AAA cannot be required as a blanket policy for entire websites.
  • Many AAA criteria are best applied selectively to critical content (e.g., government services, education, health).
  • Achieving AAA shows a strong commitment to inclusive design, but it requires significant planning and effort.

What Level Should You Strive For

You should generally strive for WCAG Level AA conformance, which includes Level A & AA.

Level AA is widely considered the standard benchmark for accessibility. It strikes a balance between inclusivity and practicality, covering the needs of most users with disabilities—including those with visual, auditory, motor, and cognitive impairments—while still being realistically achievable for most organizations.

Level AAA is aspirational, yet often difficult to fully implement across all content, so it’s typically pursued only for specific content or audiences with higher accessibility needs. But digital product contributors are encouraged to extend conformance to Level AAA when and where it makes sense.

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