There are three basic approaches for evaluating and validating the accessibility of new or existing Web sites:
In many cases a combination of these approaches will be employed. For instance, expert evaluators often use automated tools to flag areas that merit manual inspection and interpretation.
The remainder of this document offers links to further information about evaluation and validation and a list of validation tools.
Evaluating Website Accessibility. 456 Berea Street.
A series of three articles providing a comprehensive overview:
1) Background and Preparation
2) Basic Checkpoints
3) Digging Deeper.
By Swedish developer Roger Johannson.
Evaluating Web Sites for Accessibility. World Wide Web Consortium (W3C).
A must-read collection of articles on evaluating Web accessibility. Includes preliminary review, conformance evaluation, approaches for specific contexts, involving users, selecting evaluation tools, a list of tools, building an evaluation team, and a template for reporting.
Evaluating Web Sites for Accessibility with the Firefox Web Developer Toolbar. WebAIM.
An overview of using the accessibility toolbar for Firefox to test against various WCAG 1.0 checkpoints.
Testing with Screen Readers: Questions and Answers. WebAIM.
Questions and answers about the benefits of using screen readers to evaluate accessibility of a site for people with visual impairments.
Sakai Test Protocol. Sakai Project.
Description of the protocol used to assess Sakai for accessibility. Sakai is a community project to develop an open source course management system. This document could serve as an example for your accessibility statement. Document by Mike Elledge.
An accessibility validation tool may be Web-based or it could be software that you install for use from your desktop. Free Web-based tools may require you to enter the URL for each page you want to analyze. If you are validating a large site, you may wish to find a validator that will automatically analyze the entire site. Commercial tools for the desktop often are able to analyze an entire site; however, these products may cost $1000 or more.
Note that it is important to ensure that your HTML and CSS code are valid before you use an automated accessibility validator. Invalid code may inhibit the ability of a tool to evaluate accessibility. See www.w3.org/QA/Tools/.
Cynthia Says HiSoftware.
Free one-page validator. Based on commercial desktop product AccVerify (which can validate an entire site). The Web Developer Toolbar for Firefox uses Cynthia Says for accessibility tests.
Functional Accessibility Evaluator (FAE). University of Illinois at Urbana-Champaign (UIUC).
Unlike most free Web-based validators, this tool will scan entire sites (registration required). Note that this tool reflects Illinois state law and UIUC guidelines, which may not always represent MSU policies and practices.
Demonstration version of desktop testing tool is limited to analyzing one page at a time. Commercial product is a tool for Windows servers that can test entire sites; after acquiring the product you install it on your local server and your developers use it over your local Web to test against WCAG 1.0, Section 508, or U.K. or German standards.
Unlike many other tools whose reports show lines of HTML code with possible issues, this tool presents a graphical view of your chosen Web page with icons showing potential problems. This tool can be very useful for presentation to managers or in meetings because it depicts potential issues in the context of your actual page image.
Contrast Analyser. The Paciello Group.
Analyzes contrast within a Web page, e.g. between text and a background. Also simulates various kinds of visual impairments so that the developer can visualize how the page will look to people who have those impairments. Windows and Mac. Free.
HTML Validator for Firefox. Open Source.
Free plugin for Firefox. This tool validates HTML, CSS, and accessibility (Section 508 and WCAG).
Windows-based desktop application. Integrates with Microsoft Content Management System (CMS). Tests for Section 508 and WCAG 1.0. Commercial product.
Rational Policy Tester Accessibility Edition. IBM Watchfire.
Windows-based tool tests against WCAG, Section 508, as well as accessibility laws in France and the U.K. This tool is based on WebXM, a product of Watchfire, a company owned by IBM. Commercial product.
Mac OS X
The “Leopard” release of Mac OS X includes a number of features that can be used by people with disabilities or by Web developers testing a site for accessibility, including a screen reader and the ability to jump across sections of Web pages.