Web Accessibility - For Web Developers

Information for web developers on how to make your website or web application accessible to people with visual, hearing, motor, or cognitive disabilities.

This document covers Advanced Organization, Advanced Text and Images, and Advanced Audiovisual.

There is a supplementary document titled "Web Accessibility for Web Developers - Forms, Frames and Advanced Topics" that covers Advanced Forms, Advanced Frames, and other Advanced Topics.

CMS users have a parallel document titled "Web Accessibility for Users of Content Management Systems" that omits recommendations for features that are usually not controllable by a CMS user, and avoids reference to HTML elements not usually visible to someone using a GUI editor.

Advanced Organization

The same guidance is offered in Organization for CMS users, except as noted.
  • 1.3.1 Info and Relationships (for headings, lists, and table headers)

    • Semantic markup is used to designate headings (“h1”), and lists (“ul,” “ol,” and “dl”). Semantic markup is used appropriately.

      • For CMS users this is covered in the Starting Points: "Do properly nested headings create an outline of the content?" and "Are items in a list automatically numbered or bulleted?"

    • Tables are used for tabular data. Where necessary, data cells are associated with their headers. Data table captions and summaries are used where appropriate.

      • For CMS users this is covered in the Starting Points: "Does each data table include column headings?"

  • 1.3.2 Meaningful Sequence (for reading and navigation)

    • The reading and navigation order (determined by code order) is logical and intuitive.

      • For CMS users: "The reading order is logical and intuitive."

  • 1.3.3 Sensory Characteristics (for shape, size, visual location, and sound)

    • Instructions do not rely upon shape, size, or visual location (e.g., "Click the square icon to continue" or "Instructions are in the right-hand column").

      • For CMS users: similar, (but omit reference to clicking on the square icon.) This is also covered in the Starting Points: "Is the meaning the same if all text is the same color, size and font?"

    • Instructions do not rely upon sound (e.g., "A beeping sound indicates you may continue.")

  • 2.4.1 Bypass Blocks (that are repeated across web pages)

    • A link is provided to skip navigation and other page elements that are repeated across web pages.

    • If a page has a proper heading structure, this may be considered a sufficient technique instead of a "Skip to main content" link.

      • For CMS users this is covered in the Starting Points: "Do properly nested headings create an outline of the content?" It is also covered the CMS users supplement on frames.

  • 2.4.2 Page Titled (and is descriptive and informative)

    • The web page has a descriptive and informative page title.

      • For CMS users: same.

  • 2.4.5 Multiple Ways (of finding other web pages on the site)

    • Multiple ways are available to find other web pages on the site - at least two of: a list of related pages, table of contents, site map, site search, or list of all available web pages.

      • For CMS users: same, plus: "(Some of these may require assistance from the webmaster.)"

  • 2.4.6 Headings and Labels (are informative)

    • Page headings are informative. Avoid duplicating heading (e.g., "More Details") unless the structure provides adequate differentiation between them.

  • 2.4.7 Focus Visible (while tabbing through a page)

    • It is visually apparent which page element has the current keyboard focus (i.e., as you tab through the page, you can see where you are).

      • For CMS users: same, plus: "(If this is not the case, you could contact the webmaster for assistance.)"

  • 3.2.3 Consistent Navigation (across multiple web pages)

    • Navigation links that are repeated on web pages do not change order when navigating through the site.

  • 3.2.4 Consistent Identification (across multiple web pages)

    • Elements that have the same functionality across multiple web pages are consistently identified. For example, a search box at the top of the site should always be labeled the same way.


Advanced Text and Images

The same guidance is offered in Text and Images for CMS users, except as noted.
  • 1.1.1 Non-text Content

    • All images and image map hot spots have appropriate, equivalent alternative text.

      • For CMS users this is covered in the Starting Points: "Do images have appropriate alternative text descriptions?"

    • Images that do not convey content, are decorative, or contain content that is already conveyed in text are given null alt text (alt="") or implemented as CSS backgrounds. All linked images have descriptive alternative text.

      • For CMS users this is covered in the Starting Points: "Do images have appropriate alternative text descriptions?"

    • Equivalent alternatives to complex images are provided in context or on a separate (linked and/or referenced via longdesc) page.

      • For CMS users: "Equivalent alternatives to complex images are provided in context."

  • 1.3.1 Info and Relationships (for headings, lists, and emphasized or special text)

    • Semantic markup is used to designate headings (“h1”), lists (“ul”, “ol”, and “dl”), emphasized or special text (“strong”, “code”, “abbr”, “blockquote”, for example), etc. Semantic markup is used appropriately.

      • For CMS users: "Emphasized or special text uses the built in features of the CMS (italics, bold, abbreviations, block quotes, for example), etc. Such text is used appropriately." Headings and lists are covered in the Starting Points: "Do properly nested headings create an outline of the content?" and "Are items in a list automatically numbered or bulleted?"

  • 1.4.1 Use of Color (is not the only method used)

    • Color is not used as the sole method of conveying content or distinguishing visual elements.

      • For CMS users this is covered in the Starting Points: "Is the meaning the same if all text is the same color, size and font?"

    • Color alone is not used to distinguish links from surrounding text unless the luminance contrast between the link and the surrounding text is at least 3:1 and an additional differentiation (e.g., it becomes underlined) is provided when the link is hovered over or receives focus.

      • For CMS users this is covered in the Starting Points: "Is the meaning the same if all text is the same color, size and font?"

  • 1.4.3 Contrast (Minimum)

    • Text and images of text have a contrast ratio of at least 4.5:1.

      • For CMS users this is covered in the Starting Points: "Does all text have enough color contrast?"

    • Large text (over 18 point or 14 point bold) has a contrast ratio of at least 3:1.

      • For CMS users this is covered in the Starting Points: "Does all text have enough color contrast?"

  • 1.4.4 Resize text (when text size is doubled)

    • The page is readable and functional when the text size is doubled.

      • For CMS users: same, plus: "(Most browsers can change the text size in order to test this.)"

  • 1.4.5 Images of Text (not used if text alone can be used)

    • If the same visual presentation can be made using text alone, an image is not used to present that text.

  • 2.3.1 Three Flashes or Below Threshold (of flashes per second)

    • No page content flashes more than 3 times per second unless that flashing content is sufficiently small and the flashes are of low contrast and do not contain too much red. (See general flash and red flash thresholds)

      • For CMS users: similar, (except omit reference to general flash and red flash thresholds.)

  • 2.4.4 Link Purpose (In Context) (is easily distinguishable)

    • Links with the same text that go to different locations are readily distinguishable.

      • For CMS users: same. This is also covered in the Starting Points: "Is the purpose and destination of a link clear from the context?"

  • 3.1.1 Language of Page

    • The language of the page is identified using the HTML lang attribute (html lang="en", for example).

      • For CMS users this is omitted.

  • 3.1.2 Language of Parts (of page)

    • The language of page content that is in a different language is identified using the lang attribute (e.g., blockquote lang="es").

      • For CMS users: "The language of page content that is in a different language is identified using the built in features of the CMS. (If you are uncertain how to do this, you could contact the webmaster for assistance.)"


Advanced Audiovisual

The same guidance is offered in Audiovisual for CMS users, except as noted.
  • 1.1.1 Non-text Content

    • Embedded multimedia is identified via accessible text.

  • 1.2.1 Prerecorded Audio-only and Video-only

    • A descriptive text transcript (including all relevant visual and auditory clues and indicators) is provided for non-live, web-based audio (audio podcasts, MP3 files, etc.)

      • For CMS users this is covered in the Starting Points: "Does non-live audio and video content have basic transcripts?

    • A text or audio description is provided for non-live, web-based video-only (e.g., video that has no audio track).

      • For CMS users this is covered in the Starting Points: "Does non-live audio and video content have basic transcripts?"

  • 1.2.2 Captions (Prerecorded)

    • Synchronized captions are provided for non-live, web-based video (YouTube videos, etc.)

      • For CMS users this is covered in the Starting Points: "Does non-live video content have captions?

  • 1.2.3 Audio Description or Media Alternative (Prerecorded)

    • A descriptive text transcript OR audio description audio track is provided for non-live, web-based video.

  • 1.2.4 Captions (Live)

    • Synchronized captions are provided for all live multimedia that contains audio (audio-only broadcasts, web casts, video conferences, Flash animations, etc.)

  • 1.2.5 Audio Description (Prerecorded)

    • Audio descriptions are provided for all video content

  • 1.4.2 Audio Control

    • A mechanism is provided to stop, pause, mute, or adjust volume for audio that automatically plays on a page for more than 3 seconds.

      • For CMS users: same, plus: "(If this is not the case, you could contact the webmaster for assistance.)"

  • 2.3.1 Three Flashes or Below Threshold (in AV content)

    • No page content flashes more than 3 times per second unless that flashing content is sufficiently small and the flashes are of low contrast and do not contain too much red.


Optional

Optional for Advanced Organization

The same guidance is offered in Optional for Organization for CMS users, except as noted.
  • 2.4.8 Location (in a sequence of pages or complex site structure)

    • If a web page is part of a sequence of pages or within a complex site structure, an indication of the current page location is provided, for example, through breadcrumbs or specifying the current step in a sequence (e.g., "Step 2 of 5 - Shipping Address").

      • For CMS users: similar, (but omit reference to breadcrumbs.)

  • 2.4.10 Section Headings

    • Beyond providing an overall document structure, individual sections of content are designated using headings, where appropriate.

Back to Advanced Organization

Optional for Advanced Text and Images

The same guidance is offered in Optional for Text and Images for CMS users, except as noted.
  • 1.4.6 Contrast (Enhanced)

    • Text and images of text have a contrast ratio of at least 7:1.

    • Large text (over 18 point or 14 point bold) has a contrast ratio of at least 4.5:1

      • For CMS users all of 1.4.6 is omitted.

  • 1.4.8 Visual Presentation

    • Blocks of text over one sentence in length:

      • Are no more than 80 characters wide.

      • Are NOT fully justified (aligned to both the left and the right margins).

      • Have adequate line spacing (at least 1/2 the height of the text) and paragraph spacing (1.5 times line spacing).

      • Have a specified foreground and background color. These can be applied to specific elements or to the page as a whole using CSS (and thus inherited by all other elements).

      • Do NOT require horizontal scrolling when the text size is doubled.

      • For CMS users all of 1.4.8 is omitted.

  • 1.4.9 Images of Text (No Exception) (not used except for decoration)

    • Text is used within an image only for decoration (image does not convey content) OR when the information cannot be presented with text alone.

  • 2.3.2 Three Flashes (no more than 3 per second)

    • No page content flashes more than 3 times per second.

  • 2.4.9 Link Purpose, Link Only (link text alone describes the location)

    • The purpose of each link can be determined from the link text alone.

    • There are no links with the same text that go to different locations.

  • 3.1.3 Unusual Words (are defined)

    • Words that may be ambiguous, unknown, or used in a very specific way are defined through adjacent text, a definition list, a glossary, or other suitable method.

  • 3.1.4 Abbreviations (are spelled out first time they are used)

    • Expansions for abbreviations are provided by expanding or explaining the definition the first time it is used, using the “abbr” element, or linking to a definition or glossary. NOTE: WCAG 2.0 gives no exception for regularly understood abbreviations (e.g., "HTML" on a web design site must always be expanded).

      • For CMS users: similar, (except 'the "abbr" element' is replaced by 'the built in features of the CMS'

  • 3.1.5 Reading Level (of 9 years of primary education)

    • A more understandable alternative is provided for content that is more advanced than can be reasonably read by a person with roughly 9 years of primary education.

  • 3.1.6 Pronunciation (is indicated when vital to understanding)

    • If the pronunciation of a word is vital to understanding that word, its pronunciation is provided immediately following the word or via a link or glossary.

Back to Advanced Text and Images

Optional for Advanced Audiovisual

The same guidance is offered in Optional for Audiovisual for CMS users, except as noted.Back to Advanced Audiovisual



Keywords:web, accessibility, accessibility standards, Section 508, WCAG 2.0, for web developers   Doc ID:50812
Owner:Sandi A.Group:Accessibility
Created:2015-04-23 15:17 CDTUpdated:2015-06-30 13:21 CDT
Sites:Accessibility, DoIT Help Desk
Feedback:  1   0