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Website accessibility

Picture of a web browser's address bar The world wide web offers exciting possibilities for accessing large quantities of information. However, as there is no central governing authority free reign is given to individual creativity. As a result disabled and elderly people must frequently overcome additional obstacles before they can enjoy the full range of information on offer. Website accessibility is about ensuring websites are accessible and usable by everybody, regardless of disability or browsing technology.

Why be accessible?

There are several reason why websites should be made accessible for everybody:

Legal requirements

It is a requirement of UK law (Disability Discrimination Act 1995) that individuals should not encounter unjustifiable discrimination by goods, facilities and service providers on account of a disability. Under this legislation a website is considered a service, therefore, discrimination may take the form of a disabled or elderly person being denied access to a website or the provision of a poorer service by an inaccessible website.

Economic benefits

There are economic benefits to having an accessible website:

Photograph of a non-traditional browsing device
  • Disabled spending power is in excess of £80 billion therefore businesses should be making their websites accessible in order to attract disabled buyers
  • The UK population is ageing and there is also a vast amount of spending power in the older generation
  • Young professionals are accessing websites on mobile phones, PDAs and other non-traditional browsing devices. Websites need to be accessible from various browsing devices. This is quite significant considering that in 2009 it is estimated that there will be three billion mobile phone users worldwide

Workplace benefits

Employers want to attract the best employees. According to Microsoft and HiSoftware (2009) 6% of honours graduates are students with disabilities but 85% of online recruitment systems are inaccessible to them.

Much of the power of corporate intranets is that all employees can use them to access information and perform tasks. Using an accessible intranet as a communication tool improves engagement and responsiveness within an organisation.

Access for all

Having an accessible website will mean that access to information will be greatly enhanced for all individuals. When a website is designed or modified to allow access for people with disabilities it is not only making the website more accessible, it is also increasing the usability for non-disabled users. Accessible design principles, when applied correctly, benefit everyone.

Assistive technology

The majority of disabled website users make use of assistive technology. By ensuring that accessibility standards are implemented, it is more likely that a website will be more compatible with assistive technology.


  • According to comScore, the total European internet audience grew to over 240m in June 2008
  • According to Mintel, in 2008 UK online shopping expenditure topped £1 billion a month
  • The largest demographic group online is currently the 35-44 age group which accounted for 23.5% of internet visits in the four weeks up to 12 May 2007. The over 55s accounted for 22% of visits
  • 3.4 million people have disabilities preventing them from using the standard keyboard, screen and mouse set-up with ease
  • In 2006, 57% of households in Great Britain had an Internet connection: a total of 13.9 million households
  • Between January and April 2006, 15% of those aged 65 and over had used the internet
  • 36% of Britain's disabled people have access to the internet
  • If a disabled person finds a business inaccessible, 67% of their friends and family would consider not using that business themselves
  • In 2006, 2% of UK households did not have Internet access due to physical disability
  • The Riga Ministerial Declaration of 2006 states that 97% of public websites reviewed did not meet a minimum accessibility threshold
  • In 2007 between 80 and 96% of sites reviewed did not meet a minimum accessibility threshold
  • In 2007, 15.23 million UK households had Internet access
  • Of all UK households, 51% had broadband Internet access in 2007, an increase from 40% in 2006.
  • In 2007, 53% of adults purchased goods or services over the Internet

Problems encountered by disabled people and the ageing population using the internet

Blind and Partially Sighted

The way a website is designed will determine how accessible it is to people with disabilities. In particular blind people use browsers with speech or Braille output which are text-based systems; therefore the site should be navigable independent of the graphics content. For people with low vision, the ability to vary the text size on their browser is essential. A further problem encountered by blind and partially sighted people is that many websites use graphics such that they are not meaningful when accessed by a text-based browser.

Hearing impaired

People with hearing impairments require visual representation of auditory information that a website provides. With the increading use of multimedia on websites (e.g. podcasts, video streaming) it is important to ensure that information can be understood by those who have hearing impairments.

It is also important to appreciate that those using British Sign Language (BSL) use a different sentence structure and vocabulary compared to typical spoken English. Consideration should be given to using simple language and the inclusion of a glossary of terms.

A photograph of a girl with Downs Syndrome using a computer

Physically impaired

People with a physical disability may have difficulty controlling their hands and arms therefore, holding and using a mouse effectively becomes a problem. Others find prolonged use of their arms or hands tiring.

Users with physical impairments are more likely to struggle with standard computer equipment and find it easier to use assistive technology.

Cognitively impaired

People with cognitive or learning impairments may have problems reading text or become confused by complex page layouts, tables or navigation structures. Moving and blinking text may also be distracting and impede understanding.

Ageing population

While older people often experience changes in vision, hearing, dexterity, and memory as they age, they might not consider themselves to have disabilities. Yet the accessibility provisions that make webpages accessible also benefit older people with diminishing abilities. For example, many people with age-related visual impairments may benefit from being able to alter text size. Elderly people may also experience mobility difficulties when using the mouse.

Other problems encountered with web accessibility

Low bandwidth and older technologies
Many website designers work on the philosophy that the user's browser is no more than a year old. In the case of disabled and elderly users, it is likely to be considerably older than that, so there is also a problem of legacy systems.

Some aspects of Web accessibility benefit people with low bandwidth connections. Low bandwidth can be due to:

  • location - for example, rural
  • bandwidth congestion
  • connection technology - for example, mobile phone or personal data assistant (PDA)
  • financial situation - that is, cannot afford high-speed connection

Some older technologies load pages very slowly and do not support features used on newer sites.

Checklist for Web Accessibility


There are a number of methods that web site developers and designers can use to ensure web sites are accessible:

Follow guidelines

The World Wide Web Consortium (W3C), a web industry co-operative, recognised the need for universal accessibility and since 1999 its Web Accessibility Initiative (WAI) has published the Web Content Accessibility Guidelines to help reduce potential difficulties.

The WCAG 2.0 were published in 2008 and are designed to be a stable, referenceable technical standard. The Guidelines have been written using layers:

  • Principles - At the top are four principles that provide the foundation for Web accessibility: perceivable, operable, understandable, and robust.
  • Guidelines - Under the principles are guidelines. The 12 guidelines provide the basic goals that authors should work toward in order to make content more accessible to users with different disabilities. The guidelines are not testable, but provide the framework and overall objectives to help authors understand the success criteria and better implement the techniques.
  • Success Criteria - For each guideline, testable success criteria are provided to allow WCAG 2.0 to be used where requirements and conformance testing are necessary such as in design specification, purchasing, regulation, and contractual agreements. In order to meet the needs of different groups and different situations, three levels of conformance are defined: A (lowest), AA, and AAA (highest).
  • Sufficient and Advisory Techniques - For each of the guidelines and success criteria in the WCAG 2.0 document itself, the working group has also documented a wide variety of techniques. The techniques are informative and fall into two categories: those that are sufficient for meeting the success criteria and those that are advisory. The advisory techniques go beyond what is required by the individual success criteria and allow authors to better address the guidelines. Some advisory techniques address accessibility barriers that are not covered by the testable success criteria. Where common failures are known, these are also documented.

A summary of the main WCAG 2.0 recommendations:

  • All non-text content has a text alternative that serves the equivalent purpose
  • Use the alt attribute to describe images and animations
  • Captions or audio description are provided for audio content
  • CSS is used for a consistent design but content is still presented in a logical order if the style sheet is removed
  • Form controls are labelled
  • Use good contrasting colours for backgrounds and text (minimum 4.5:1, enhanced 7:1)
  • Use relative sizing instead of fixed so text is resizable up to 200%
  • Text is not justified
  • Computer mouseEnsure functionality is available through the keyboard as well as the mouse
  • Ensure plug-ins do not "trap" the keyboard
  • Pages do not time out, refresh, move, blink, scroll, or auto-update without the presence of a mechanism for the user to control or disable them
  • Ensure animation can be paused or switched off
  • Minimize the occurrence of content that requires timed interaction
  • Provide skip links (e.g. Skip to content, Back to top)
  • Web pages have titles that describe topic or purpose
  • Provide clear navigation mechanisms
  • Link text makes sense when read out of context
  • Provide a site map, table of contents or search facility
  • For page organisation, use headings, lists and consistent structure
  • The language attribute for each page is set
  • Mechanisms are provided for identifying specific definitions of words or phrases used in an unusual or restricted way and for identifying the expanded form or meaning of abbreviations and acronyms
  • Ensure documents are clear, simple and that text which requires a reading ability more advanced than the lower secondary education level (after removal of proper names and titles) has a version that requires a lower reading ability
  • Errors are detected, identified and described, and suggestions for correction are provided
  • All mark-up is validated and coded correctly

Other accessibility techniques

  • Website developers should take steps to familiarise themselves with how disabled people use the web e.g. how assistive technology can be used to interpret web sites
  • Involve disabled people with a range of impairments in the process of design and development
  • Use a selection of web browsers to view the website (e.g., Firefox, Internet Explorer, Netscape Navigator)
  • Examine pages using specialised browsers (e.g. Home Page Reader, Lynx)

Automated testing tools

  • Make use of operating system and browser accessibility functions
  • Use an automated accessibility testing tool

Below are a selection of automated tools that web designers can use to help test the accessibility of a website:


Further information


The information contained in this section was taken from the following sources:

Picture acknowledgements