Understanding the WCAG Conformance Levels A, AA, and AAA – Web Accessibility FAQ
As you are learning about website accessibility compliance, at one point you will inevitably ask the question: “Should I do WCAG Level A, AA, or AAA?” Search forums and other blogs and most of the information you will read will leave you even more confused. in this article I will explain the three levels and help you understand which to follow.
First, a little background on the Web Content Accessibility Guidelines (WCAG). The WCAG is a set of standards that has been evolving for 20 years. Because of the many website accessibility lawsuits going on, many people think that the WCAG is new. Quite the opposite. It was created by the Web Accessibility Initiative (WAI) of the World Wide Web Consortium (W3C) and first published on the 5th of May, 1999. Its purpose is to enable people with disabilities to have access content on the internet.
Over the years, the WAI has updated the Guidelines to reflect technological updates. The most recent update, WCAG 2.1 has seventeen new standards. It was released on June 5th, 2018, about ten years after its previous version, WCAG 2.0.
This is important to know because it shows that the Guidelines were created – and continue to be maintained – by a very knowledgeable and serious group. In case you do not know it, The W3C is the international non governmental body that creates the global standards and protocols on how to use the internet. Yes, they are the highest authority on how the internet works.
Aware of the complexities involved in making a website fully accessible, the WAI created three levels of compliance, from basic to full compliance. Below I will explain each level and provide examples to help you understand how they differ in complexity and how each level makes a website more accessible than the previous.
Level A consists of 30 criteria and is the lowest compliance level. It provides a guideline for the bare minimum a website needs to be accessible to people using assistive technology. The standards in Level A have very low impact on the user interface (design) of the site, as they deal mainly with how information is presented. For example:
- 1.2.1 Audio-only and Video-only (Prerecorded), requires that you have an alternative way to present the information on prerecorded audio and video files. For example, you can provide transcripts, enabling people with cognitive, hearing, and visual impairments to access the information. For video files you can also provide an audio-only description of the content of the video.
- 3.3.2 Labels or Instructions, instructs webmasters to clearly label any field that requires users’ input (i.e. forms). This standard helps people with visual and cognitive impairments to understand what action they need to take on each field, as well as in which format the information must be inputted. For example, for a phone number field on a form, use the following label Enter your phone number as (XXX)XXX-XXXX.
- 4.1.1 Parsing, requests that you have clean and error-free Hypertext Markup Language (HTML) on your website. HTML provides the basic structure for your web content. If there are errors in the HTML, assistive technology software might not be able to convert the information on the site to a format accessible to the user. Clean and error-free HTML will also help all visitors to have a more pleasant experience on your website.
This brings us to an important point. All the success criteria in WCAG Level A improves the user experience (UX) to everyone, ensuring clean and modern coding, as well as giving options on how to consume the information. Level A is far from being ideal, but it is a good start.
Level AA encompasses all 30 criteria on Level A plus an additional 27 criteria. Level AA compliance often requires some changes on the design. In many ways, it is a step further on the web accessibility journey, as it builds upon previous standards, but it also introduces new ways to make a website accessible. For example,
- 1.2.5 Audio Description (Prerecorded), requests that pre recorded videos in “synchronized media,” such as webinars and videos, have captions. This standard is an evolution of 1.2.1, explained above. While 1.2.1 simply requires a transcript of videos, to comply with 1.2.5 you need to also add captions. It is more laborious and it makes your site more user-friendly.
- 2.4.7 Focus Visible, states that when using a keyboard to navigate the site, as opposed to a mouse, there must be a visible indicator showing where the keyboard navigation is focusing. This indicator guides users as to where on the page they are.
- 3.2.3 Consistent Navigation, ensures a good UX for everyone. All menus that repeat on multiple pages must follow the same order. This means that you cannot change the order in which a button will go on the menu. If your menu starts with a link to the Home page, then Services page, followed the About, Contact, and Blog, then you must follow that same order (i.e. Home, Services, About, Contact, and Blog) everywhere you have this menu.
- 4.1.3 Status Messages, indicates what you need to do when your website provides a status message, such as confirmation that a message was sent successfully. In these cases, you need to use Accessible Rich Internet Applications (ARIA) roles so the message is presented to people using assistive technology, but it does not receive focus.
Level AAA is the last step on the web accessibility journey. It is where everyone should strive to arrive. It includes the 57 criteria from the two previous levels and another 20 criteria. To comply with Level AAA, you must be in compliance of all 77 criteria on the WCAG 2.1. Meeting these criteria require more work than those on the previous levels, as they often require custom coding and adaptations on the user interface. However, they also ensure full website accessibility compliance and great user experience. Some of its standards are evolutions of standards on the previous levels and others are new concepts. For example:
- 1.26 Sign Language (Prerecorded), requests that webmasters add sign language to all pre recorded videos. This standard is a continuation of criteria 1.2.1 and 1.2.5 explained above, making it easier for people with hearing impairments to access the contents of videos on the site.
- 2.1.3 Keyboard (No Exception), stipulates that a person can use all the features of a website with just a keyboard, without being constrained by a certain amount of time for each keystroke. Similar to criteria 2.4.1 and 2.4.7, it empowers people who rely solely on a keyboard to navigate a website.
- 3.1.6 Pronunciation, requires that webmasters provide the pronunciation of words that have different meanings depending on the pronunciation. These words are called heteronyms. For example, the word “tear” means to rip something apart when it is pronounced “tair” and it means the liquid substance that comes out of the eyes when someone cries, when pronounced “teer”. People who can read well might be able to discern the meaning of the word based on the context in the sentence. However, people with visual or cognitive disabilities who rely on text-to-speech software might have a hard time understanding the meaning of the word if the software uses an erroneous pronunciation. Therefore, to be fully compliant and accessible, you need to provide the correct pronunciation
As you compare the standards above from each level, you will certainly notice that the complexity and difficulty in complying with the level increases significantly as you go from Level A to AA to AAA. Hopefully, you can also understand how much more accessible – and user friendly – a website becomes as you escalate to the next level.
You might also have noticed that on Levels A and AA I provide four example criteria, each starting with a different number from one through four; 1.2.1 (A), 1.25 (AA), 2.4.1 (A), 2.47 (AA), 3.3.2 (A), 3.2.3 (AA), 4.1.1 (A) and 4.1.3 (AA). Yet, on Level AAA I only included examples that started with number one through three. The first number on a criterion determines the web accessibility principle it follows. There are four principles in total. They are: Perceivable, Operable, Understandable, and Robust. Level AAA does not have any criterion from the Robust principle. This is why I only gave you three examples from it.
So, which level should I follow?
The ideal, as I wrote above, is to follow Level AAA. However, it might not be possible to be in AAA compliant on every page on your website. The WAI understands that it can create too heavy a burden to comply with all 20 Level AAA criteria on the entire website. In their words, “[i]t is not recommended that Level AAA conformance be required as a general policy for entire sites because it is not possible to satisfy all Level AAA Success Criteria for some content.”
This is the main reason why most organizations focus on meeting Level AA only. At minimum, your website must comply with the 30 criteria on Level A and the 27 criteria on Level AA. If you are able to follow the criteria from Level AAA, then go right ahead. It will make your website more accessible and user friendly and certainly help you to avoid ADA website compliance lawsuits.