Which set of web accessibility standards or guidelines should I comply with?

Web accessibility means making a web page viewable and usable by everyone. View video, "Access for All", for more information.

Which set of web accessibility standards or guidelines should I comply with?

CSULA requires Section 508 standards at a minimum. However, the World Wide Web Consortium (W3C) has established its own set of Web Content Accessibility Guidelines (WCAG) that contain additional measures for making pages more universally accessible. Web authors and develops are encouraged to also comply with the guidelines from W3C.

What is appropriate alternate text for purely decorative images?

If an image is purely decorative and contains no informative content, use an empty string as the "alt" attribute, i.e., alt="". This technique is widely supported by screen readers, which respond by ignoring the image.

How long can an “alt” attribute be?

The HTML specification does not define a maximum length for "alt" attributes. However, their intended function is to provide short, efficient alternate text so that users who cannot see an image can access the content presented in the image. Browsers' and certain assistive technologies' current method of rendering "alt" attributes reinforces the need to keep them short.

What is the current recommendation for providing long descriptions for complex graphics?

In HTML, the "longdesc" attribute was specifically designed to link to a page that describes complex graphics. Although historically this attribute has not been well supported by assistive technologies, current and recent versions of most screen reader applications do support it.


What is a “skip to the content" link?

A "skip to the content" link is a same-page link that allows screen reader users and users navigating by keyboard to skip past redundant navigation systems and jump efficiently to the main content of the page, just as a sighted user can do at a glance.

In addition to including a skip to the content link, how else can I facilitate page navigation?

All web documents should be divided into short sections for readability, and should be organized using a clear hierarchy of HTML headings and subheadings (i.e., <h1>, <h2>, etc.) This helps all users to understand the document contents, but it especially helps users of screen readers. Most screen readers include functionality that allows users to jump between headings with a single keystroke, so blind users can effectively scan the document looking for sections that particularly interest them, just as sighted users typically do.

Is it possible to develop an accessible dynamic menu?

A variety of experiments have focused on developing accessible dynamic menu systems. None of the models is fully accessible to all users; most require that the user have Javascript enabled, and none can be activated by handheld computer users. Therefore, the only way to ensure that all users have access to secondary menus is to populate the primary menu items with links that lead users to a separate page or pages where they can access the secondary menu items.

Is it reasonable to expect that all users today are using Javascript-enabled browsers?

Javascript is well supported but not ubiquitous. Javascript is not accessible to users with certain assistive technologies, older browsers, pocket versions of browsers, text-based browsers such as Lynx or Emacs/W3, or newer browsers that have scripts disabled to eliminate possible security risks.


There are many different types of color blindness. How can I ensure that color blind users can access my site?

A variety of tools are available to help with evaluating the accessibility of color combinations, including a tool that allows users to sample their websites as they might be viewed by someone with any of three types of color blindness, and tools that measure whether particular color combinations have sufficient color and brightness contrast. A general rule is that any information that is communicated with color (e.g., "fields with red labels are required") should also be communicated with some mechanism other than color (e.g., bold text, marked with an asterisk). This way, a user who is unable to perceive color can still access the information.

What is wrong with using HTML tables for layout?

HTML tables were originally intended to be used for presenting tabular data, not for layout. The W3C discourages the use of tables for layout because they are striving for a web in which content and structure are completely separate from presentation. In the W3C's world view, CSS is the vehicle by which presentation and layout are defined. Browser support for CSS has improved significantly in recent versions, and growing numbers of sites are migrating over to CSS entirely for positioning.

How do I make data tables accessible?

Data tables are tables used to represent actual tabular data, with rows and columns of related information. The technique for making data tables accessible depends on the complexity of the table but may involve any of a combination of TH and CAPTION elements and/or "summary", "scope", "id", and "headers" attributes.

To make a form accessible, is it enough just to be sure that form labels appear immediately to the right of the fields they represent?

The key accessibility problem with HTML forms is that screen readers typically have to guess which label goes with which field. If a form consists solely of text fields and labels always appear immediately to the right of the fields they represent, a web author can be reasonably confident that screen readers will read this correctly. However, confidence goes down as forms become more complex, and accessible markup must be used in order to prevent screen readers from having to guess.


Are “QuickLinks” dropdown lists accessible?

A growing number of websites use a single drop-down list of links that takes the user immediately to a selected link, without requiring that the user press a Submit button. For people who can't use a mouse because of a visual impairment or physical disability, these form fields present problems since they automatically select the first field that a user arrows to and activate that link. The user is therefore unable to scroll down any farther in the list. The solution is to always provide a Go button and to avoid using onSelect or onChange events in dropdown lists.

Is PDF Accessible?

With the release of Acrobat 5.0, Adobe unveiled a new type of Portable Document Format (PDF) called "tagged PDF." It is the only type of PDF that is optimized for accessibility, including support for alternate text for graphics and an underlying document structure that resembles HTML. Adobe Acrobat 8 has added new accessibility features and made improvements to features included in earlier versions. Anyone still using earlier versions of Acrobat is encouraged to upgrade.

Can I build an accessible online application using Macromedia Flash?

With the release of Flash MX, Macromedia had made significant improvements to its product's ability to produce accessible content. Using Flash's Accessibility Panel, developers can assign text to interface elements so that screen reader users can access them. In some Flash applications, developers can explicitly define a tab order for keyboard users. Flash accessibility depends on authors to create accessible content and on assistive technologies to support the accessibility features. Only a few currently do.

Are frames accessible?

Frames are not in and of themselves inaccessible. Keyboard users and assistive technology users are able to navigate among the various frames that comprise a web page. In order to facilitate navigation, each frame must be assigned a title (using the "title" attribute) that clearly communicates the function of the frame (e.g., "Navigation" or "Content"). Also, screen reader users should be provided with clear instructions on how and where to locate content within the frameset.

Where can I learn more about web accessibility?

You may visit the rest of the pages in our Accessibility site to find a list of various websites, tips and software.