The relationship between accessibility and search engine optimisation

Accessibility, the process of making a website accessible to all users, has a number of commonalities with SEO (search engine optimisation). An accessible site ensures the main elements of a web page, including navigation, content, images and forms, are accessible to users. When a site is optimised for search engines, there is a very similar process of ensuring the content is accessible to spiders who crawl and index each page.

Below are a number of key points where these two disciplines overlap:

Providing relevant words within anchors

For Users – Users with disabilities need to know where links are pointing. For instance, a page containing content about blue widgets will be more accessible with ‘blue widgets’ within the anchor than ‘click here’.

For Search Engines – Search engines such as Google place a large amount of importance on links including internal site links. By providing a keyword-rich anchor you are telling the search engine that ‘blue widgets’ is the page topic. This will add weight in the SERPs (search engine results page) when a user inputs in this phrase.

Provide text for non-text elements

For Users – Users who cannot see an image will know what it is via the description, using tag elements such as the ‘alt’. This point is very important for sites using image-based navigation.

For Search Engines – Search engine spiders are also unable to view images, so ensuring keyword rich descriptions will also add weight to the page for target phrases.

Off-loading unobtrusive scripts within the HTML

For Users – Large scripts being inserted into HTML is very unobtrusive to users using screen readers. Javascript and CSS can easily be off-loaded into external files. This is also a logical step in terms of creating maintainable web sites.

For Search Engines – Search engines will also read code such as Javascript as page content. By off-loading it to an external file you are ensuring that search engines will index only the keyword-rich content which again adds weight to the SEO effort.

So to round up my post, we can say that, in essence, an accessible website is, by default, search-engine friendly.