Accessibility means that something can be used, obtained, approached, entered or reached, etc. Two meanings applicable to the Internet can be derived from this. First, the provision of Internet access to people with disabilities or elderly people as barrier-free as possible, and secondly, accessibility and readability of a website for a crawler.

Accessibility in terms of freedom from barriers[edit]

The Internet is now generally regarded as free space which is designed to be accessible to a large number of people. Accessibility plays an important role in this context. As part of the W3C, the Web Accessibility Initiative (WAI) stands for the idea that the Web should be usable to as many people as possible. The WAI has been striving to achieve this since 1997. To facilitate physically restricted users’ access to information on the Internet, the WAI has compiled several guidelines since 1999:

  • Web Content Accessibility Guidelines (WCAG): These include information on website programming standards and also cover content, technology, as well as design.
  • Authoring Tools Accessibility Guidelines (ATAG): Here, special conditions apply to tools that are used for creating web pages.
  • User Agent Accessibility Guidelines (UAAG): These guidelines define the conditions which should be met by browsers or media players.
  • Web Accessibility Initiative, Accessible Rich Internet Applications (WAI-ARIA): This policy is to ensure that through meta data and special function, widgets and web applications can also be used by blind people.

The W3C has published a checklist for webmasters.

Accessibility and SEO[edit]

Accessibility is an important concept for SEOs as well, because it relates to the creation of websites in such a way that the content and technical structure can be easily accessed by search engine spiders. One could therefore come to the conclusion that perfect accessibility is the result of perfect on-page optimization.

The following are important factors in providing maximum accessibility and readability of a website crawler:

  • Clean source
  • A clear site structure as with heading tags
  • A clear structure of the content, for example, with paragraphs, bold or italics
  • The provision of relevant content in text and image or moving images
  • No content that is hidden by JavaScript
  • No complicated flash animations
  • No broken links
  • The sensible use of meta-information such as title or description to identify content clearly[1]

Limits of optimization[edit]

Especially for SEOs, the temptation is great to over-optimize a website. The accumulation of keywords (stuffing) is a significant factor. Therefore, before engaging in any accessibility optimization, any SEO should ask himself whether these improvements will ultimately create additional benefits for human users.


  1. Google SEO and web accessibility Accessed on 11/28/2014