9.9. Tools to Help Check Accessibility

The next set of tools is used to ensure that web applications conform to accessibility standards.

9.9.1. W3C HTML Validation Service

The very first line in HTML files should be the document type (doctype) the doctype is an instruction interpreted by web browsers to know what version of markup the page was written in. This allows the browser to render the page accordingly. HTML validators ensure that your markup complies to the standard declared by the document type at the top of your HTML page.

Figure 9-34. Fangs rendering a web page

The W3C HTML Validation Service (http://validator.w3.org/) is a free tool presented as a web page, where a URL can be entered and the W3C HTML Validation Service will report any issues where the HTML is noncompliant to the document type specified. The example in Figure 9-35 shows errors that were found on http://www.mcwherter.net/blog using the W3C Markup Validation Service.

Figure 9-35. W3C HTML Validation Service

9.9.2. W3C CSS Validation Service

Very similar to the W3C HTML Validation Service, the CSS Validation (http://jigsaw.w3.org/css-validator/) will parse the CSS contained on a page and report any errors found. The example in Figure 9-36 shows two errors on http://www.mcwherter.net/blog using the ...

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