This concept analysis of web accessibility considers:

  1. Uses
  2. Essential and non-essential features
  3. Perspectives guiding its practices and policies
  4. Research and practitioner definitions
  5. Examples


The concept of web accessibility has three interrelated but somewhat separate uses.

  1. Foundationally, web accessibility is an egalitarian goal that aims to see the technology and content of the World Wide Web (Web) be made available to and usable by people, universally. Originally concerned strictly with removing barriers to finding and using information, as experienced by people with disabilities, the concept has evolved to more broadly seek digital inclusion for people facing barriers for other reasons, including social and economic.

    Efforts to achieve web accessibility are seen as essential steps toward achieving equality for, and social inclusion of, people with physical and cognitive disabilities, aging populations, as well as people who are geographically, politically, economically, socially or otherwise marginalized (“Introduction to web accessibility,” 2019; United Nations Department of Economic and Social Affairs, 2012, p. 15-50; Yesilsa, Brajnik, Virgo, & Harper, 2012).
  2. The term “web accessibility” is also used a descriptor for policies, principles (“Accessibility principles,” 2019) and practices that aim to aid people with physical and cognitive disabilities or socio-economic barriers to use the Web. For example, “web accessibility policy” or “web accessibility evaluation tool.”
  3. Finally, web accessibility is used as a descriptor for the measure of the usability of websites by people with one or more disabilities/barriers. The degree to which a page or site is considered “accessible” is generally guided by, and measured against, relevant guidelines and standards set by standardization organizations, such as the Accessibility for Ontarians with Disabilities Act (AODA) or the W3C’s international standard: Web Content Accessibility Guidelines (WCAG 2.0).

The concept of web accessibility is applied to a wide range of topics including: assistive technology (e.g. screen readers); web browsers, media players and other user agents; techniques/practices (code/ development, design, web content, information architecture); user experience (UX) issues for people with disabilities (e.g. page load times, colour use, tab-navigation); users’ adaptive strategies; authoring tools (software); guidelines and standards; evaluation tools and methods; education and awareness-raising efforts, legislation (“Essential Components of Web Accessibility”, 2019).

Essential and non-essential features

A review of literature from the 1990s to the present day suggests four essential features of web accessibility, noted below with related non-essential features.

  1. The starting point for thinking about web accessibility, and its first essential feature, requires that people look at the Web – websites and digital content along with the related tools and technologies – through the lenses of people with physical and cognitive disabilities (or people who experience other barriers) to identify inequities of access and barriers to usability.

    An associated, but non-essential feature would relate to the specific types of inequities and barriers. They might include but not be limited to a user community’s ability to: find, understand, navigate, interact with and create/contribute to web content and/or web technology.
  2. The next essential feature could be characterized as a quest for “equity.” All web accessibility efforts essentially stem from two core beliefs related to equity. These beliefs have become somewhat interwoven over time.
    • The power of the Web is in its universality. It is critical that the Web be usable by anyone.
      – Tim Berners-Lee, World Wide Web Consortium (W3C) Director, and inventor of the Web.
    • Equal access to information and information production is essential to the full and equal enjoyment of all human rights and fundamental freedoms by all persons with disabilities.
      – United Nations Convention on the Rights of Persons with Disabilities and Optional Protocol, 2007.

      There are a number of non-essential features that relate to this quest for equity. (1) Efforts may improve the universal experience of seeking and contributing to the Web, thereby supporting its long-term relevance and vitality. (2) Efforts may reduce digital alienation, aid in social inclusion and remove inequalities in society (3) Efforts may additionally benefit business interests, educational interests, political interests, or other institutions.
  3. The third essential feature is that all web accessibility efforts – the goal, policies/practices and systems of measurement – aim to remove barriers to finding and using the information and services provided through the Web, which are experienced by people with physical and cognitive disabilities.

    As the concept is evolving to address the needs of other marginalized communities, a non-essential feature is that efforts may also aim to remove barriers experienced on the basis of geography, socioeconomics, age, or other. Additionally, efforts may aim to remove barriers to the production and publishing of web content. (See Definitions section for more.) Finally, it is generally believed that web accessibility efforts will likely result in practices that universally benefit web users or more broadly improve the usability of the Web.
  4. The final essential feature to consider is that web accessibility efforts assume that technological solutions are required to remove what are understood to be technological barriers to use. Efforts may result in, or include, legislative solutions that require developers to comply with set standards. Efforts may have measurable outcomes, but these are not essential features.


There are two international bodies leading thought and action on web accessibility.

W3C logo
The power of the Web is in its universality. It is critical that the Web be usable by anyone.

Tim BERNERS-LEE, World Wide Web Consortium (W3C) Director, and inventor of the Web

The World Wide Web Consortium (W3C), and within that the Web Accessibility Initiative (WAI): This body represents industry, disability organizations, accessibility researchers, government, and others interested in web accessibility. From within the structure of the W3C, they approach the concept from the perspective of working to improve the mechanisms of the web as well as people’s experience of it.

UN logo

Equal access to information and information production is essential to the full and equal enjoyment of all human rights and fundamental freedoms by all persons with disabilities.

United Nations Convention on the Rights of Persons with Disabilities and Optional Protocol, 2007

The United Nations (UN), and within that the Convention on the Rights of Persons with Disabilities: This body is made up of state parties who approach the concept from the perspective of working to “…recognize the inherent dignity and worth and the equal and inalienable rights of all members of the human family as the foundation of freedom, justice and peace in the world…”

Both perspectives colour and inform each other as well as the ways researchers (including those cited here), practitioners and policy makers approach and apply the concept.

Nothing about us without us.

mantra for the Disability Rights Movement

It is critically important to note that there are numerous strong, progressive, grassroots organizations, activists, and people sharing their experiences with barriers to access who stand behind, along side and in front of these organizations, shaping perspectives on web accessibility. Their voices inform and evolve the concept of web accessibility from it’s static roots, into to dynamic, lived experiences.

Research and practitioner definitions

Petri, Savva and Power note in Towards a Unified Definition of Web Accessibility (2015) that “Web accessibility is a complex and multi-component concept, which perhaps needs a range of definitions.” Nevertheless, they attempt to draft a unified definition, believing it valuable as a (1) guide for empirical studies (2) gauge for progress and (3) means to identify knowledge gaps in and between the components of the concept.

They looked at definitions of web accessibility drawn from a range of books, papers, standards guidelines and online sources from 1996 – 2014 and from authors in 21 different countries. By comparing 50, for the purpose of the paper, they were able to identify six components that were common to the definitions. Using those common elements, they composed the following unified definition of the concept: “all people, particularly disabled and older people, can use websites in a range of contexts of use, including mainstream and assistive technologies; to achieve this, websites need to be designed and developed to support usability across these contexts.” (Petri, Savva & Power, 2015)

This attempt addresses the essential elements, however it lacks specificity for practitioners and policymakers alike, and it ultimately provides little to measure against. Petri, Savva and Power do praise the WAI definition of web accessibility for including a clear set of user actions:

“Web accessibility means that websites, tools, and technologies are designed and developed so that people with disabilities can use them. More specifically, people can:

•           perceive, understand, navigate, and interact with the Web

•           contribute to the Web”

And Petri, Savva and Power further note that “contribute to” is a use that is commonly been missed from academic and practitioner definitions (with the noteworthy exception of Harper and Yesilada.) But if we think of web accessibility as a concept that encompasses an egalitarian goal for social inclusion, the other side of the inclusion coin would be participation, which would require the ability to create / contribute. Likewise, if the concept is used as a descriptor for policies and practices, or as a descriptor for a measure of usability by people with one or more disabilities, surely researchers, practitioners and policymakers should embrace an understanding and definition of the concept that is as concerned with enabling and measuring people’s ability to create content as consume it.

Subsets, further examples, and non-examples

Web accessibility is a subset of universal design, which looks beyond the accessibility (or non-) of technology and is concerned with the design of products, environments, programmes and services. (United Nations Convention on the Rights of Persons with Disabilities, 2007)

  • An example of universal design that is also an example of a web accessibility practice is: coding and writing “alternative text” to describe images on a website. The practice allows a screen reader to read the content of the image to a blind user, is an example of a practice that originally was conceived to address web accessibility concerns. The practice also provides image context/descriptions to search engine crawlers, which helps engines index images properly, making it more likely the information contained in the images will be served to users in search results, disabled or not. (, n.d.)
  • An example of universal design that is a non-example of web accessibility is: “curb cuts.” Originally designed to allow people in wheelchairs to roll onto sidewalks, curb cuts make it easier for various users to access sidewalks (people pushing strollers, cyclists accessing sidewalk lockups, elderly, etc.)

Web accessibility is also a subset of information communication technology accessibility (ICT accessibility), which is concerned with communication devices and applications such as radio, television, cellular phones, computers, satellite systems as well as network hardware and software and associated services, including the Web. (“Information communication technology accessibility”, n.d.)

There is a complex relationship between the concepts of “accessibility” and “usability” though the terms are sometimes used interchangeably. Typically, web accessibility problems could be seen as a subset of usability problems. (Yesilada, Brainik & Vigo, 2012)

It also seems important to include an example that can illustrate the essential feature: a technical solution is required to address technical barriers.

  • An example of a web accessibility practice is: Correctly using headers (H1, H2, etc.) and titles on an employment website. This practice allows a search engine to identify the relevance of the content (thereby serving it to interested job searchers) and allows a blind user using a screen reader to navigate for relevant information about the job posting or application process.
  • A non-example of web accessibility is: using a website to publish a paragraph that states X is an equal opportunity employer and everyone is welcome to apply.

Additional uses and applications of the technology and practices originally designed for web accessibility often emerge. Web accessibility tactics and practices commonly have additional applications that reach beyond the traditional experience of the Web, including: voice command technologies; voice command search (e.g. Alexa and Google Assistant); mobile technologies and applications; software development and other applications. In addition, web accessibility practices including design/layout and writing practices are often applied to digital documents for internal use, work product, personal use, etc.

Related concepts: Mobil accessibility; Web content accessibility, Digital Accessibility; Digital inclusion; User Experience (UX); perceived accessibility.


Berners-Lee, T. 1997. W3C Leads program to make the web accessible for people with disabilities (Press release on the launch of WAI).

Khosrow-Pour, D.B.A., M. (2013). Dictionary of Information Science and Technology (2nd Edition, 2013) [“web accessibility policy,” “web accessibility evaluation tool”] Hershey, PA: IGI Global. doi:10.4018/978-1-4666-2624-9

Moz. com [“Alt-text”]

Oxford Dictionary [“Web”, “Accessibility”]

Petrie, H., Saava, A. & Power, C (2015) Towards a unified definition of web accessibility

United Nations, [“Information communication technology accessibility”]

United Nations, Convention on the Rights of Persons with Disabilities (CRPD) Retrieved from

(1) (2)

United Nations Department of Economic and Social Affairs (2012). United Nations expert meeting on building inclusive societies and development through promotion of accessible information and communication technologies (ICTs); emerging issues and trends.

World Wide Web Consortium (W3C) [“Accessibility introduction,” “Essential components of web accessibility,” and “Accessibility principles”] Retrieved from:


Yesilada, Y., Brajnik, G & Vigo, M. & Harper, S. (2012). Understanding web accessibility and its drivers. W4A 2012 – International Cross-Disciplinary Conference on Web Accessibility. 19:1-19:9.