Accessibility Evaluation Tools
- Different Classifications of Accessibility Evaluation Tools
- Which Tool is Best?
- List of Accessibility Evaluation Tools
Many web designers, developers, and evaluators are introduced to web access through accessibility tools. All accessibility tools perform automated checks of web pages for accessibility issues and all generally have additional features, but each tool targets different audiences. In order to help web designers, developers, and evaluators choose an appropriate tool for their purposes, this section discusses the general types or classifications of accessibility tools.
However, web accessibility requires more than just accessibility tools; it requires human judgment. It is important to remember that accessibility tools can only partially check accessibility through automation. The real key is to learn and understand the web accessibility standards rather than relying on a tool to determine if a page is accessible or not.
Different Classifications of Accessibility Evaluation Tools
There are many different types of evaluation tools that can be used to determine whether or not web content is accessible. This section will focus on the classification and usage of different evaluation tools, and what web designers, developers and evaluators should know about these classifications.
Standards and guidelines used
One key in understanding accessibility tools is to understand the standards to which the tool was developed. When deciding which accessibility tool will work best for you it is important to consider the standards and guidelines used by the different accessibility evaluation tools. There are currently two standards and guidelines most commonly used. These are the Web Content Accessibility Guidelines 1.0 (WCAG 1.0) and Section 508 of the United States Rehabilitation Act.
WCAG 1.0 consists of three priority levels that act as an industry standard. The first level, Priority 1, covers items on web pages that must be made accessible in order for individuals with disabilities to access the content at all. The second level, Priority 2, includes items on web pages that should be made accessible to allow a wider group of users to access the content. The third level, Priority 3, describes items on Web pages that can be made accessible to allow the widest amount of individuals with disabilities to use the site. For more information about WCAG 1.0 visit the W3C web site - external link.
Similarly, Section 508 of the United States Rehabilitation Act outlines the requirements for making federally-funded web sites accessible to individuals with disabilities. These standards detail how different components of web sites need to be designed to make the web content accessible. Under Section 508, the U.S. federal government has 16 standards that are used to define web accessibility. For more information about Section 508 visit the Section 508 checklist.
Free vs. commercial
One very important classification of tools to the budget conscious web designer, developer, or evaluator is the cost. There are many excellent free evaluation tools out there, but perhaps after weighing the specific needs of your organization and the features you need you may decide that a commercially available tool is best for you. When this decision is made it will be important to keep in mind:
- Who will be using the tool. The evaluation tool, and its associated cost, will depend a great deal on the accessibility knowledge of the one using it. Free tools often assume a greater understanding and spend less time educating their user.
- The size of the site being examined. Those tasked with maintaining or creating a very large web site will need accessibility tools that spider through the site so they don't have to check the site one page at a time. Often times it is the commercially available tools that have this feature. Free tools often limit their scope to checking just one page at a time.
- The information that must be collected. This varies depending on your situation. Some developers may be required to provide detailed reports on the accessibility of many different types of web documents. Commercially available tools often produce more detailed and specific reports.
Another important classification of accessibility evaluation tools involves where these tools are meant to function. Some tools are available at a web site where they are able to evaluate the content of a page quickly and easily without downloading or installing an application. Other options include tools that are created as extensions to a browser, tools that function as part of a web authoring tool. Finally, some tools require installation on your hard drive or server like other pieces of software.
There are many tools, and especially free ones, that are used online. They work by having the site visitor input the URL of their web page, selecting from any evaluation options, and then selecting a "Go" button or some other method of initializing the program.
Examples: Cynthia Says, WAVE, WebXact
Within a browser
Several accessibility tools have been created as extensions for the more popular Internet browsers (Internet Explorer, Netscape, Firefox, and Mozilla). After being downloaded and installed they provide extra menu options within the browser itself. Some of these extensions create toolbars that remain visible within the browser. All accessibility extensions provide a variety of useful tasks to evaluate the page that is currently in the browser window.
Examples: AIS Accessibility Toolbar, Web Developer Extension for Mozilla-based Browsers, Accessibility Extension for Internet Explorer, Accessibility Extension for Mozilla/Firefox
Install on hard drive
Many of the more powerful accessibility evaluation tools require that they be installed on your hard drive or server like other pieces of software. These tools are useful when working on very large and complex sites. They are able to examine web pages local to your machine or behind your company's firewall.
Examples: Deque Ramp, InFocus by SSB
Accessibility evaluation tools can also be classified in terms of what they examine or their scope. Some tools are very simple and limited in scope so they evaluate just one page at a time and check for just a few things. Other tools are very specific in what they evaluate and focus on just one element of a web site. Then there are very detail oriented tools that are able to examine large sites and check for a variety of errors.
One page at a time
Tools that evaluate just one page at a time are often those accessibility evaluation tools found online and as part of a browser. Their functionality is limited to evaluating content found at just one URL.
Many accessibility tools focus on just one element of a web site. They may demonstrate what the site looks like to someone who is blind or has low vision. Some tools may show the site content from the perspective of someone who is colorblind. This limited scope is is commonly found in tools available online and as part of a browser.
Accessibility evaluation tools that require installation of software are often able to examine large sites and check for a variety of errors. These tools are meant for enterprise level organizations with a large web development staff, and more specific requirements. This is a feature found in commercial software tools.
Evaluation only vs. evaluation and repair
Another important classification of accessibility evaluation tools deals with the repair functionality of these tools. Many tools can only perform an evaluation, but some tools are able to perform the evaluation and guide the repair process. This is a more common characteristic of commercially available tools. These often spend time educating their user and guiding both the evaluation and repair process.
Accessibility tools generate a variety of reports based on the results
of an analyzed web page. According to the World Wide Web Consortium's
Web Accessibility Initiative (WAI)
all accessibility tools should look at a web page for both obvious errors
(such as missing
alt text) and warn users
of the need for manual checks (i.e. the appropriateness of the alternative
text for the image). However, beyond the general requirement for tools,
accessibility report styles differ widely depending on the target audience
familiarity with web design and web accessibility standards. Web designers,
developers, and evaluators who know which style best meets their needs
will be able to choose an appropriate tool.
Text-based report styles are the most common type of accessibility report. These reports generally list the specific guideline being used to scan the page and the instances of each type of accessibility error. Some also show the source code of the page where the error occurs.
This report style uses special icons to highlight accessibility errors and manual check issues on a web page. With this kind of report, the icons are integrated into the web page's graphical user interface next to the item on the page with an accessibility issue.
An Evaluation and Reporting Language (EARL) report is a machine readable report of the accessibility standard the page validates to, as well as the accessibility issues highlighted in the report, the date of the evaluation, and any manual checks that need to be performed by developers. The EARL reports are an attempt by the W3C to standardize accessibility reports and help users compare the effectiveness of accessibility tools.
Which Tool is Best?
Depending on your needs, different types or classifications of evaluation tools offer different report formats, additional features, and benefits that can help you choose a tool for your situation. So which tool is right for you? That depends on your skill set and how you define your web responsibilities. Web designers, developers, and evaluators each have different needs.
Web designers generally have competency with graphic design, HTML mark-up, Cascading Style Sheets, and scripting languages. Web designers are generally involved with the "front-end" creation of web sites.
Web developers combine knowledge of computer programming languages with database design to create the "back end" of most web sites. Web developers have a solid understanding of mark-up languages.
Web evaluators generally serve web site teams as administrators. Evaluators focus their attention on checking the site to see if it meets organizational, national, and international standards. In some situations, web evaluators have less knowledge of HTML code and therefore can look at the whole web site from a different perspective.
Accessibility tools provide web designers, developers and evaluators with a great first step toward web accessibility. However, it is important to remember that using tools to check for accessibility is just the first step toward web access. Web designers, developers, and evaluators who understand WCAG 1.0, WCAG 2 and Section 508 Guidelines and how they should be implemented into web sites will be able to help a web development team more than any tool.
List of Accessibility Evaluation Tools
- A2 solutions Visualisation Tool - external link: Alpha Squared Solutions.
- Accessibility Review Tool - external link: UB Access. Free next-generation tool enables asessment of website's meeting legislation and needs of the disabled.
- Accessibility Valet Demonstrator - external link: WebThing
- Accessify.com - external link: Tools, links and resources.
- AccMonitor Online - external link: Hi-Software
- AccVerify, AccRepair - external link: Hi-Software
- AIS - Web Accessibility Toolbar - external link: National Information and Library Service (NILS), Australia. Toolbar aids manual examination of pages for accessibility features.
- Anybrowser - Screen Size tester - external link: Enables you to test how your page appears at low screen resolutions.
- A-Prompt - external link: University of Toronto's Adaptive Technology Resource Centre (ATRC) and the TRACE Center
- AskAlice - external link: SSB Technologies
- Colour Contrast Test - external link: Juicy Studio. Tests foreground/background color contrast.
- Color Blindness Check - external link: Q42. View a web site as someone with color blindness would.
- Colorblind Web Site Filter - external link: View actual web pages through the eyes of visitors with three different types of color blindness.
- Color Vision - external link: Cal Henderson. Test web site foreground/background colors for their contrast and clarity to color blind visitors.
- Cynthia Says - external link: Hi-Software. Accessibility agent offering validation for WAI standards and Section 508 compliance.
- Deque Ramp - external link: Deque. Cross-platform solution for testing and remediating web sites and web based applications for integrated accessibility.
- Hermish - external link: A free on-line accessibility and browser compatibility checker.
- HiSoftware.com Accessibility and Quality Tester - external link: Tests to Section 508 and WCAG standards.
- InFocus - external link: SSB Technologies
- LIFT - external link: UsableNet
- Lynx Viewer - external link: Delorie online viewer enables you to view your site in a text browser.
- Macromedia Dreamweaver/UsableNet Accessibility Extensions - external link:
- OCAWA Accessibility Validator - external link: OCAWA, Operational Control and Analysis for Web Accessibility. Tests the accessibility of a Web site using international accessibility standards.
- Sitemorse - external link: Web content governance, monitoring, recording and benchmarking tool.
- TAW - external link: Sidar in Spanish.
- Torquemada - external link: WebxTutti in English and Italian. English:
- UITest.com - external link: Type a site address once and test the Web site with the W3C, WDG, ATRC, WebAIM, WebXact, Bobby, Cynthia Says, HiSoftware, Site Valet, Colorblindness filter, and Google Viewer.
- Vischeck - external link: Allows the user to see the world as color blind people see it. Checks by images and URLs.
- WAVE 3.5 - external link: WebAIM. Online tool checks page accessibility, displays page with tags to show good and bad points.
- Webnauts - external link: A collection of popular tools.
- Webthing Accessibility Valet - external link: This tool will examine a site based on a selected accesibility level and then provide the source code with marks next to each element which requires attention.
- WebXact - external link: Watchfire.
- AIS Accessibility Toolbar - external link
- Cynthia Says
- Markup and Robustness Evaluation Tools
- Web Developer Extension for Mozilla-based Browsers