May 27 2020

Understanding WCAG 2.1 ADA Levels

We've moved into a new phase of website accessibility and conformance. No longer are organizations weighing the benefits making their websites compliant with the Americans with Disabilities Act (ADA). Instead, it's become a best practice to ensure websites work for all potential users. And by ensuring that sites work for the 61 million Americans with a disability, organizations have made their sites easier to use for everybody, have improved their SEO and have lowered their risk of legal repercussions. 

American sites across all industries and all levels of government have reached the consensus that Web Content Accessibility Guidelines (WCAG) Level AA is not only the best practice, but also the law.  But why Level AA? If AA is good, wouldn't AAA be better? And is Level A "good enough for now"? Let's compare the different website conformance levels so that you understand why AA is the standard and why your next redesign should require design and development against these standards.

Level AAA Conformance

Level AAA is better for those with disabilities than Levels AA and A. For instance, for those with poor vision, AAA sites are easier to see. For those with poor or no hearing, AAA guarantees that American Sign Language is available for all videos in addition to synchronized closed captions. But sites that adhere to Level AAA standards are generally unattractive for those with no disability, and the ADA doesn't aim to jeopardize the experience of one user group for the benefit of another user group. Further, it's often difficult for site owners to maintain a AAA site. For instance, the site owner would be responsible for knowing how the screen reader pronounces all words on the site and then providing explanation for all words mispronounced. This would be difficult for most site owners if there were only one screen reader, but with NVDA, JAWS, VoiceOver, and Narrator heavily used, this is impossible for most. 

Level AA Conformance

Level AA is the sweet spot. It ensures enough measures are in place so that as many can use the site as possible regardless of their ability. And it does so without jeopardizing how a site looks or works for the majority of users nor does it put a heavy burden on the site owner. If one has a visual perception disability, the colors will have enough contrast for most to see. If one is blind, the screen reader can read all content. For one who navigates with a keyboard, everything can be reached. Level AA sites work well and don't provide an unsurmountable burden for site owners. In other words, it enables the most people to use a site, which is ultimately the goal of website ADA conformance.

Level A Conformance

Unlike Level AAA and AA, Level A conformance may be considered a good start towards making a more comformant website but there are several notable criteria missing that allow sites meeting this standard to be considered truly conformant. For example, a Level A site has no color contrast requirements so many of the 7.6 million Americans with a visual disability have no way to see the site, or at least will struggle unnecessarily to do so. For those who rely on a keyboard to navigate instead of a mouse, there is also no requirement to show focus, so keyboard navigation is difficult. These examples are all-or-nothing endeavors. There is no foundation that could be set now that will help provide AA standards later. 

But there are standards in Level A that are helpful. Level A requires captions on videos, thereby helping the millions who do not hear well or at all. Level A also limits flashing content so that those prone to seizures are not likely to be triggered by a site.

While creating or maintaining a site against Level A standards would be helpful, it simply does not go far enough because it does not meet the current WCAG 2.1 standards put forth by the ADA. Further, it would not protect the site owner from a well-meaning lawsuit. 

Comparing Level A, AA and AAA Features

Below is a broader comparison of specific website features and how they are addressed, or not, with the level of conformance included in the WCAG.

Feature Level A Level AA Level AAA

Provide text alternatives for any non-text content

Provide alternatives for video-only and audio-only content

Add captions to all prerecorded videos with sound

Provide additional medial or describe movements that provide extra information in prerecorded video that not are audibly explained in the video

Include captions for live videos

Describe movements that provide extra information in prerecorded video that not are audibly explained in the video  

Provide sign language translations for videos



Record alternative video with extended audio description



Provide a transcript for video and audio content



Include closed captions with live audio



Ensure all content has intuitive page structure and formatting

Use meaningful sequence of content

Provide instructions via more than one sense

Do not restrict content to be viewed in only one orientation  
In forms, assign input purposes to appropriate fields  
Implement appropriate input purposes on all form fields, icons, and regions    

Do not rely only on color to convey information

Provide end-user control of audio

Use minimum color contrasts


Resize text up to 200%


Limit the use of text within images


Ensure contrast is at least 7:1 relative to the background


Limit background noise on video and audio content



Allow users to customize their view



Restrict images of text


Allow content to be enlarged to 400% without forcing the user to scroll horizontally  
Ensure active controls have sufficient color contrast  
Allow end users to override text spacing with no loss of content or functionality  
Ensure popup content remains visible until the user chooses to dismiss it  

Confirm that all parts of a site are keyboard-accessible

Allow keyboard user to navigate away from all parts of a site

All parts of a site must be keyboard-accessible with no exceptions


Confirm keyboard shortcuts can be manipulated by the user

Allow time limits to be adjustable for the user

Provide a mechanism so that moving, blinking, scrolling, or auto updating can be user paused, stopped, or hidden

Confirm that no time limits are enforced



Ensure no interruptions of content consumption



Confirm that if re-authentication is necessary, data previously entered is saved


Warn users if inactivity will result in data loss    

Ensure that no content flashes more than three times in a second

Ensure that no content flashes more than three times in a second with no exceptions


Allow animations from interactions to be disabled    

Provide Skip to Content links

Ensure page titles are descriptive of the page content

Confirm that the focus order is logical

Clarify the purpose of every link

Provide multiple ways for users to find pages


Ensure headings organize content and that all elements are labeled


Confirm that the keyboard focus is clear


Ensure user always knows location on the site



Ensure every link’s purpose is clear even when using the link out of context


Ensure every new topic has a heading


Confirm that site can be operated via single clicks or touches
Activate controls with 'mouseup' and 'touchend', not with 'mousedown' and 'touchstart'
Include visible text in the programmatic label
Confirm that if gestures are part of the interface, also include additional means of use
Provide that all touch targets are at least 44x44 pixels    
Confirm types of input modalities are not restricted    

Ensure every page has a defined language

Confirm that language changes on a page are communicated


Avoid or explain all jargon



Explain all abbreviations



Write for reading level of 9 years of school



Explain words that a screen reader will have trouble pronouncing



Confirm that content does not change on focus

Confirm that content does not change on input

Ensure that menu usage is consistent across site


Ensure that icons and buttons are obviously icons and buttons


Confirm that elements on the site do not change unless the end-user asks



Clearly describe form input errors

Provide clear form input instructions with labels

Clearly describe form input errors and how to fix them


On forms, validate input and allow input to be changed


Provide instruction for completing tasks, especially forms



On forms, validate input and allow input to be changed without exception



Confirm that HTML is validated against standards

Confirm that all content generated by scripts is accessible

Ensure that content changes generate an alert for the screen reader user  

If you have questions about website ADA conformance or are looking to talk services with us, our team at ZAG is happy to help you.
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posted by
Dan Seagull
Dan Seagull
Sr. QA & Certified Accessibility Analyst

ZAG Interactive is a full-service digital agency in Glastonbury, CT, offering website design, development, marketing and digital strategy to clients nationwide. See current job openings.
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