Learning about WCAG accessibility standards

What are WCAG accessibility standards?

WCAG is an abbreviation for Web Content Accessibility Guidelines.

Introduction to Web Accessibility and W3C Standards (Source: YouTube & WC3. Accessed on 06 Nov 2020)

These guidelines were originally published by the World Wide Web Consortium (known as W3C), in order to get more web developers to focus on accessibility for people with disabilities and limited devices (for example, screen readers, mobile phones and tablets).

Whilst the publication of WCAG 2.0 was in December 2008, WCAG 2.0 only became a recognised ISO standard (for ISO/IEC 40500) in October 2012.

Versions of WCAG accessibility standards

Oftentimes, you might notice that WCAG accessibility standards come in multiple versions, starting from WCAG 1.0. As with any guidelines, they must be updated to accommodate technological progress and changes in legislation.

Major differences within versioning between WCAG 1.0 and 2.0 accessibility standards

Between WCAG 1.0 and WCAG 2.0 accessibility standards, the major difference has been the way the guidelines have been organised.

Within WCAG 1.0 accessibility standards, there was more of a checklist approach to guidelines in the form of priorities; 1, 2 and 3. However, WCAG 2.0 accessibility standards focus on the four design principles of web accessibility, giving them different levels of standards instead of priorities.

Standards of WCAG 2.* accessibility standards

Within WCAG 2.* accessibility standards, there are not only multiple versions, but also multiple levels of standards.

According to WC3, there are three levels of accessibility standards, which are outlined below:

Standard levelCriteria
Level AFor Level A conformance (the minimum level of conformance), the Web page satisfies all the Level A Success Criteria, or a conforming alternate version is provided.
Level AAFor Level AA conformance, the Web page satisfies all the Level A and Level AA Success Criteria, or a Level AA conforming alternate version is provided.
Level AAAFor Level AAA conformance, the Web page satisfies all the Level A, Level AA and Level AAA Success Criteria, or a Level AAA conforming alternate version is provided.
Levels of WCAG 2.* accessibility standards (Source: Understanding WCAG 2.0, W3C. Accessed on 06 Nov 2020)

Testing for WCAG 2.* accessibility standards

Can the testing of WCAG 2.* accessibility standards be automated?

With the release of WCAG 2.0 accessibility standards, WC3 stated that testing guidelines can be more automated (in comparison to WCAG 1.0 accessibility standards); however, they also stated that it requires human evaluation.

Looking at things manually can actually be a good thing because it focuses on a human user experience. For example, we can consider a web page that uses media queries and viewports: from a robot’s perspective, the web page is perfectly mobile-friendly. However, from a human’s perspective, the text could be overlapping, it could have elements missing, and the whole page could appear distorted to the human eye.

Unless there is an automatic test that can successfully test and interact with the web page, human evaluation is necessary for optimal accessibility to be reached.

The four design principles of web accessibility for WCAG 2.* accessibility standards

As stated briefly above, according to WC3, there are four design principles of web accessibility.

Design principleCriteriaGuideline link
PerceivableInformation and user interface components must be presentable to users in ways they can perceive.View guidelines
OperableUser interface components and navigation must be operable.View guidelines
UnderstandableInformation and the operation of the user interface must be understandable.View guidelines
RobustContent must be robust enough that it can be interpreted by a wide variety of user agents, including assistive technologies.View guidelines
Design principles of WCAG 2.* accessibility standards (Source: How to Meet WCAG 2.1, WC3. Accessed on 06 Nov 2020)

When to consider implementing WCAG 2.* accessibility standards

Depending on the level of WCAG 2.* accessibility standards you’re seeking to implement (A, AA or AAA), it can really cause a strain on resources. For instance, you have to allocate budgets to consider extra development, manual testing, and even multiple re-testing.

It 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.


If your website is part of the UK public sector

On the 23rd of December, 2018, the UK government enforced a new legal requirement for the public sector. Specifically, this accessibility regulation is called the Public Sector Bodies (Websites and Mobile Applications) (No. 2) Accessibility Regulations 2018.

“People may not have a choice when using a public sector website or mobile app, so it’s important they work for everyone. The people who need them the most are often the people who find them hardest to use.”

“At least 1 in 5 people in the UK have a long term illness, impairment or disability. Many more have a temporary disability.”

UK Government Digital Service team

The UK Government Digital Service team states that if your website is a part of the public sector, then you must comply with WCAG 2.1 AA accessibility standards; however, there are exemptions to this.

Please note, RKWO Ltd (the company behind is not a government-affiliated body or website. Accessibility standards and regulations change and are updated from time to time, therefore, if you are considering implementing WCAG accessibility standards, please consult with your government for their advice.

If you’re considering better SEO

As part of Google Chrome’s developer tools, Google offers a reporting system called Google Lighthouse, which covers website performance, accessibility, best practices and SEO.

Google Lighthouse test results for RKWO
Google Lighthouse test results for RKWO (Source: Google Chrome & RKWO. Accessed on 06 Nov 2020)

SEOs believe that Google has essentially given developers a tool that allows website developers to build better websites — allowing websites to perform better within Google’s search engine.

With that said, a lot of Google’s Lighthouse report checks overlap with WCAG 2.* accessibility standards. Therefore, taking the effort to ensure your website is compliant with WCAG 2.* accessibility standards will likely improve your Google Lighthouse score, which could indirectly improve your SEO score, too.

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