Accessibility is not just about making sure that people with disabilities can use your site. It is also about allowing a wide variety of users and devices to have access to information, thus maximizing your potential audience by letting users experience the website as they choose. Designing for accessibility means accepting that, for online information, there is:
- no standard user on the Web, and
- no standard device for browsing information.
An accessible website doesn't exclude visitors due to their abilities, or the method they choose to access the web.
Accessible websites make clear content, structure, and ease of navigation a priority over the frillier aspects of design. This doesn't mean they are visually unattractive, nor does it mean they are prevented from using the latest web technologies, provided that all information is still accessible to users.
Strive to provide web content that meets accessibility guidelines as defined by the World Wide Web Consortium (WC3).
Basic Criteria for an Accessible Site
- Images. Use the ALT attribute to describe the function of each visual (Appropriate Use of Alt Text) (Choose the Best Images).
- Multimedia. Provide captioning and transcripts of audio, and descriptions of video (UUA.org Policy on Transcripts and Captions for Video).
- Keyboard controls. Make sure every control on the page is usable with keyboard commands (Keyboard Accessibility).
- Hypertext links. Use text that makes sense when read out of context. For example, avoid "click here" (Meaningful Links, Brief Links). Don't open new windows.
- Page organization. Use headings, lists, and consistent structure (White Space, Meaningful Headers).
- Color. Sufficient contrast between text and background helps the visually impaired as well as those using devices in bright sunlight (Luminosity Colour Contrast Ratio Analyser), but too much contrast can hurt readers with dyslexia (Color Contrast Check: shoot for brightness difference over 125 and color difference between 500 and 600).
- Graphs and charts. Summarize or use the longdesc attribute.
- Scripts, applets, and plug-ins. Provide alternative content in case active features are inaccessible or unsupported.
- PDF files. HTML is always the preferred format for web documents. If you use PDFs, be sure they are not just images of text or captured but non-edited text (Accessible PDFs).
- Frames. Do not use frames. Frames have many accessibility and usability issues.
- Tables. Make line-by-line reading sensible, and summarize (Accessible Tables).
- Forms. Use the label attribute and review your form's instructions and keyboard controls (Accessible Forms).
- Check your work. Make sure your code is validated. Cross-browser compatible XHTML has the best chance of being accessible to the greatest number of browsers.
The Unitarian Universalist Association (UUA) uses the more detailed Accessibility Checklist for Websites to evaluate the accessibility of UUA.org.
Tools for Testing a Page
- The Web Developer extension adds web developer tools to a browser, allowing you to easily turn off styles or scripts.
- Cynthia Says is designed to identify errors in your content related to Section 508 standards and/or the Web Content Accessibility Guidelines (WCAG).
- Tingtun Page Checker shows the guidelines and what needs improvement. Includes code validation.
- Functional Accessibility Evaluator checks for violations and gives a tabular view. Check HTML5 and Accessible Rich Internet Applications (ARIA) techniques or HTML4 legacy techniques.
- WAVE Web Accessibility Tool displays checks visually over the website itself.
- 6 Surprising Bad Practices That Hurt Dyslexic Users: Web accessibility doesn’t only extend to color blind users, but dyslexic users too.
- Seven Screen Reader Usability Tips
- Web Content Accessibility Guidelines
- Simple Usability Tips with Samples
- Disability & Accessibility for Congregations