Web accessibility

What is web accessibility? The great challenge for achieving an Internet for everyone

Internet Diversity Integration

There are barriers on the Internet that affect millions of people with disabilities around the world. These days, citizens with motor, sensory and cognitive difficulties are becoming ever-more dependent on advances in web accessibility to enter the mainstream of educational, economic and social development.

accesibilidad web
Web pages must be created in line with accessibility criteria

We spend an average of six hours and 43 minutes surfing the Internet every day, according to the Digital 2020 report published by We Are Social and Hootsuite. In spite of this, the Internet continues to be out of reach for the vast majority of the world's people with disabilities, according to the international World Wide Web Consortium (W3C) through its Web Accessibility Initiative (WAI).


Web accessibility combines programming, design and technology to build a barrier-free Internet that allows all users to understand, learn, navigate and fully interact with the Web. Like industry and architecture that design objects, vehicles and spaces adapted to the needs of people with reduced mobility or cognitive, visual and hearing problems, the Internet must also go down this road.

The global WAI initiative is the driving force behind this work, which ensures that websites and their content fulfil usability and universal accessibility criteria that allow all Internet users to navigate the web regardless of physical, intellectual or sensory limitations. Accessible websites also benefit from other aspects such as more potential visitors, faster loading speeds, improved positioning and online reputation (TrustRank), bandwidth savings, and enhanced compatibility with browsers and devices, etc.


The WAI has been issuing standardised, internationally recognised guidelines for creating more accessible content and pages since 1999. These technical recommendations, which are aimed at webmasters, designers and developers, are regularly updated and are grouped into the three blocks summarised below:

 Web content accessibility guidelines (WCAG)

Guidelines for creating accessible content compatible with all types of assistive technologies, devices, browsers and programming languages. They include the use of large fonts, adaptive designs, predictive texts, browsing assistants, etc.

 Authoring tool accessibility guidelines (ATAG)

Standards concerning software and application development used to create, manage and publish digital content. These tools include word processors, database managers, video editing programmes, etc.

 User Agent Accessibility Guidelines (UAAG)

Guidelines for developing the programmes needed to interact with web content, such as browsers, media players, screen readers, etc.


The WAI also classifies the web pages according to content accessibility, establishing the following levels:

  • Level A: this is the least demanding and includes pages that meet certain conformity criteria determined by the WCAG, such as the availability of subtitles for recorded audio or text alternatives for audiovisual content, etc.
  • Level AA: this is the intermediate level and the most usual requirement of bodies that issue web accessibility certifications. It includes websites that fulfil more advanced criteria such as the availability of subtitles for live audio, audio description, adjustable text size, etc.
  • Level AAA: this is the strictest level and consists of websites that comply with the most demanding criteria, such as sign language interpretation, extended audio description, explanation of abbreviations, absence of elements that flash more than three times per second, etc.
WAI* activities to promote web accessibility.


​​​​​​​  SEE INFOGRAPHIC: WAI* activities to promote web accessibility [PDF]


Some online applications are able to quickly and simply check the degree of accessibility of web pages. This shows which aspects of the website need improvement to make it more accessible according to the WCAG guidelines. Here are some of the most commonly used apps:

  • Web Accessibility Test (TAW): this tool for designers and developers can automatically determine accessibility of a site in relation to WCAG 1.0 and WCAG 2.0 guidelines. In both cases, the TAW generates a report with the test results.
  • HERA: this tool is only available for WCAG 1.0 guidelines. In this case, it carries out an automatic and prior analysis of the website, alerting to the errors found and aspects to review.