About WCAG

Compliance Requirements

Selecting a Level of Conformance

Each level of accessibility can represent goals with which organizations and websites should aim to conform. Depending on the website — whether it’s a site being retrofitted to improve its state of accessibility or if it’s a new website being developed — the conformance goal may vary.

As you’ll recall, Level A allows most people to access the content of a website. While Level A conformance is an honourable accomplishment, it is generally considered “minimal conformance.” If you are working with a limited budget (or no budget) this may be an acceptable level of accessibility. However, as mentioned earlier, it is generally accepted that most sites should strive for Level AA and, perhaps, should conform with a few of the Level AAA success criteria (defined below).

If you are working on a new website, Level AA should be the goal from the start. Assuming the developers know what needs to be done, there is very little extra effort required to jump from Level A to Level AA. If you are working with an existing site that is receiving an accessibility retrofit, then you may want to first aim for Level A, then with time resolve all Level AA issues. Generally, it is less costly to build a site to be accessible from the start than it is to build a site and retrofit it later to conform.

Level AAA conformance is unattainable for many websites. While it is possible to conform with some of the requirements at this level, they can often be counterproductive or unnecessary. Take for instance the reading level requirement (WCAG 2.0, SC 3.1.5). Public organizations will want to meet this guideline, reducing the reading level required to understand their website’s content and thereby reaching the broadest audience possible. But for other sites that focus on a particular or highly educated audience, it may be impossible or even inadvisable to comply with this requirement. Imagine an advanced book in biomechanics written at the lower secondary school reading level required to satisfy this guideline. If it were possible, replacing the advanced terminology and jargon with low-level paraphrasing would likely make the content unusable by the intended audience.

Other Conformance Considerations

In addition to meeting all the Level A, AA, or AAA requirements, there are other conformance requirements to consider before being able to claim conformance at one of these levels:

  • Full pages: Conformance applies to full web pages only. It cannot apply to parts of pages.
  • Complete processes: When a conformance claim is being made on a collection of pages that make up a web application, for instance, all pages in the collection must conform. If one were to claim “the discussion forum conforms at Level AA,” then all aspects of the forum must conform — logging in, reading posts, posting new messages, and so on.
  • Accessibility supported: Techniques to implement accessibility requirements are done in a way that is supported by assistive technologies. For example, there is a linked image, which when clicked, opens a feature. The linked image does not have alt text to describe the function of the image but does include text nearby that says “click the button to open the feature.” This example would not be accessibility supported. Even though the image has been described with text, it has not been described in a way that assistive technologies can make use of it. In this case, by adding alt text to the image, it would be considered accessibility supported because assistive technologies can read alt text. Accessibility support is a very complex issue with many grey areas. Read through “Understanding Accessibility Support” for a discussion of other things to consider when assessing accessibility support.
  • Non-interference: When non-accessible technologies are used and accessible alternatives are provided, the inaccessible version must not interfere with access to the accessible version. For instance, an embedded Flash object may have a link to an accessible HTML version on the page following the object. If, while navigating through the page by keyboard or using assistive technology, the cursor becomes trapped in the Flash object, it is interfering with the accessible version that follows. In this case, even though an accessible version is provided, it cannot be accessed; thus, the page does not conform. If a bypass link were provided to skip over the Flash object, and users were able to back out of the object, the page would then conform. Ideally, the Flash object should be created in a way that does not trap the cursor.

Making Conformance Claims

Once a website has addressed all the issues required for a certain level of conformance, it may be desirable to “claim” conformance, though there is no requirement that a claim be made in order to conform.

Basic Conformance Claim

A basic claim must include the date the site was judged to be conformant. Since web content tends to change over time, conformance can typically only be claimed for a specific date (with exceptions such as numbered versions of web software). The basic claim must also include the specification or standard the site is claiming conformance with, and it must include the level of conformance. A basic conformance claim may look like the following:

On January 20, 2019, this site conformed with the Web Content Accessibility Guideline 2.0 at Level AA.

A conformance claim can be more extensive than just a basic claim like that described above. It can also provide documentation about the accessibility features found on a website, so those accessing the site with assistive technologies can read about these features rather than having to discover them on their own. This documentation is often found linked prominently in the navigation elements of a website, usually near the start of a page so it is easily found by assistive technology users, and it is often labelled “Accessibility” or “Accessibility Statement.”

If the conformance claim does not apply to the whole site (e.g., there may be some older content that remains inaccessible), the scope of the claim should also be specified. For instance, add to the basic claim above, “…for any content added to the site after January 1, 2012.” The claim can also list known issues if there are areas of the site that are known to be inaccessible, perhaps because there isn’t a suitable accessible alternative to a particular technology being used. For example, “…the video conferencing area of the site remains non-conformant due to the lack of an alternative accessible conferencing system.”


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Introduction to Web Accessibility Copyright © 2019 by The Chang School, Toronto Metropolitan University is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License, except where otherwise noted.

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