Introduction to accessibility testing

By now you will be well aware that accessibility testing focuses on making the web accessible for users with disabilities but it can help in many other ways such as making it easier for all of us to use web pages and for search engines to find them!

Conformance testing

One pillar of accessibility testing is ‘conformance testing’ to check whether web pages comply with existing standards.

Alongside guidelines, WCAG 2.0 defines conformance requirements that you have to meet if you claim to comply with WCAG, for instance:

  • One conformance level (A, AA, AAA) must be met.
  • Conformance must be achieved for the full page. No part of a page must be excluded from conformance checking.
  • All web pages that are needed to complete a process must conform at the specified level based on a series of success criteria made up of the elements within webpages. For example, on a shopping site, if the first page of the payment process is covered by the conformance level, all other pages that take you from the ‘shopping cart’ to the payment and the order confirmation must also be included.

The WAI (Web Accessibility initiative) has published a demo illustrating the improvement of a web site by applying the WCAG 2.0 In the next step we will show you how conformance testing is applied practically.


User testing

WCAG 2.0 does not claim to cover all issues that people with disabilities may encounter in web content. For this reason, checking conformance to WCAG 2.0 does not prove that a website is accessible to everybody. A real accessibility evaluation should therefore also include user testing.

User tests allow you to identify issues that depend on:

  • a users’ wide variety of requirements,
  • user skills and abilities needed to use the web service
  • the input and output technologies they use
  • specific design issues.

User testing will give you valuable feedback as to how your web site actually works for the group of people you invited to take part but just as with all individuals those with disabilities also have varying skills and abilities and may differ in the way they use their assistive technologies.

User involvement in accessibility testing can be formal or informal, depending on your goal and your budget. Simple and informal tests can be sufficient to help you resolve specific problems or to check whether a new interaction method works with a screen reader. For example, you may ask an experienced user of assistive technologies, such as Carole, to follow a specific scenario that involves the new interaction method that you want to add to your site.

More formal user tests can help you collect data on specific accessibility problems, functionalities or web pages. User tests can involve open discussions while a user is performing specific tasks on your website. Accessibility tests like this do not typically cover subjective measurements such as general satisfaction, effectivity or efficiency when performing tasks although comments might well spill over into what could be considered usability testing.


There are links related to this topic available from the bottom of this page.


© This work is a derivative of a work created by Technische Universität Dresden, and licensed under CC-BY BY 4.0 International Licence adapted and used by the University of Southampton. Erasmus + MOOCs for Accessibility Partnership.

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This article is from the free online course:

Digital Accessibility: Enabling Participation in the Information Society

University of Southampton