Skip to main content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Do you know how to create accessible digital products and services? This guide recaps relevant Web Content Accessibility Guidelines (WCAG)requirements and calls out specific considerations for content, design, and development. It also clarifies how developers should work together with designers and content creators to ensure that federal websites and digital products meet the Revised 508 Standards.

The profound impact of disability on user experience cannot be underestimated, shaping not only accessibility but also the very essence of inclusivity in design. A study by the World Bank shows that accessibility technology can make website navigation possible or easier for 57% of all computer users.

If you are a developer, designer, or content manager, keep reading! Bookmark this guide and refer to it whenever you’re developing new content, websites or digital tools.

How To Use This Guide

Major topics are listed below in alphabetical order. Click on a topic name to jump to that topic for an explanation of the WCAG requirements (also known as Success Criteria) related to that topic.

Audio-Only or Video-Only

1.2.1 Audio-only and Video-only (Prerecorded)

For prerecorded audio-only and prerecorded video-only media, the following are true, except when the audio or video is a media alternative for text and is clearly labeled as such:

Content/Design Considerations

Development Considerations

1.4.2 Audio Control

If any audio on a web page plays automatically for more than 3 seconds, either a mechanism is available to pause or stop the audio, or a mechanism is available to control audio volume independently from the overall system volume level.

Failure to meet this requirement could interfere with any use of the page. Refer to Requirement 5 - Non-Interference to learn more.

Content/Design Considerations

Development Considerations

2.2.2 Pause, Stop, Hide

For moving, blinking, scrolling, or auto-updating information, ALL of the following are true:

Failure to meet this requirement could interfere with any use of the page. Refer to Requirement 5 - Non-Interference to learn more.

Content/Design Considerations

CAPTCHA

1.1.1 CAPTCHA

If the purpose of non-text content is to confirm the content is being accessed by a person rather than a computer, then text alternatives that identify and describe the purpose of the non-text content are provided, and alternative forms of CAPTCHA using output modes for different types of sensory perception are provided to accommodate different disabilities.

Content/Design Considerations

Development Considerations

Changing (Dynamic) Content

4.1.2 Name, Role, Value

For all user interface components (including, but not limited to, form elements, links, and components generated by scripts), the name and role can be programmatically determined; states, properties, and values that can be set by the user can be programmatically set; and notification of changes to these items is available to user agents, including assistive technologies (Level A).

Development Considerations

2.2.2 Pause, Stop, Hide

For moving, blinking, scrolling, or auto-updating information, ALL of the following are true:

Failure to meet this requirement could interfere with any use of the page. Refer to Requirement 5 - Non-Interference to learn more.

Content/Design Considerations

Contrast

1.4.3 Contrast (Minimum)

The visual presentation of text and images of text has a contrast ratio of at least 4.5:1, except for the following:

Content/Design Considerations

Flashing

2.3.1 Three Flashes or Below Threshold

Web pages do not contain anything that flashes more than three times in any one second period, or the flash is below the general flash and red flash thresholds.

Failure to meet this requirement could interfere with any use of the page. Refer to Requirement 5 - Non-Interference to learn more.

Best Practice: Do not have content that flashes.

Forms

1.3.1 Info and Relationships

Information, structure, and relationships conveyed through presentation can be programmatically determined or are available in text.

Content/Design Considerations

Development Considerations

    <style>  
    fieldset {  
    border: 0 none;  
    }  
    </style>
    
    <fieldset>
     <legend>Your Name</legend>
     <label for="title">Title (optional)</label>
     <input id="title" type="text">
     <label for="first-name">First name*</label>
     <input id="first-name" name="first-name" type="text" aria-required="true">
    <label for="middle-name">Middle name (optional)</label>
    <input id="middle-name" type="text">
    <label for="last-name">Last name*</label>
    <input id="last-name" name="last-name" type="text" aria-required="true">
   </fieldset>
   

3.2.2 On Input

Changing the setting of any user interface component does not automatically cause a change of context unless the user has been advised of the behavior before using the component. Examples of changes in context are:

  1. Opening a new window
  2. Moving focus to a different component
  3. Going to a new page (or anything that would look to a user as if they had moved to a new page)
  4. Significantly re-arranging the content of a page

Content/Design Considerations

Development Considerations

3.3.1 Error Identification

If an input error is automatically detected, the item that is in error is identified and the error is described to the user in text.

Content/Design Considerations

Development Considerations

Best Practices:

  1. Move focus to error/success message.
  2. Set error/success message container to tabindex=”-1”. Otherwise, focus cannot be set successfully on the message.
  3. Provide a count of errors.
  4. Associate error descriptions with form fields using aria-describedby so that screen reader users know how to fix the problem.
  5. Make error messages visible so that sighted users know how to fix the problems.
  6. Place error messages adjacent to the inputs so that screen magnification users can easily see which messages belong to which fields.

Tip: How to use “Alert” versus “Alert Dialog”

  1. An alert (role=”alert”) does not require a user action. It does not move the keyboard focus. No part of the page is hidden or obscured or made unavailable at any time.
  2. An alert dialog (role=”alertdialog”) requires a user action. It acts like a regular dialog, but it is supposed to convey more of a sense of urgency. Screen readers typically say “Alert dialog” when an alert dialog pops up. The focus moves to the dialog and the user is required to take action. Usually this means clicking a button, even if it may just be an “OK” button or a “Close” button. The user cannot navigate out of the dialog by just tabbing, and screen reader users cannot use keyboard shortcuts to access semantic elements (headings, landmarks, form elements, etc.) that are outside of the dialog.

3.3.2 Labels or Instructions

Labels or instructions are provided when content requires user input.

Content/Design Considerations

3.3.3 Error Suggestion

If an input error is automatically detected and suggestions for correction are known, then the suggestions are provided to the user, unless it would jeopardize the security or purpose of the content.

Content/Design Considerations

Development Considerations

For web pages that cause legal commitments or financial transactions for the user to occur, that modify or delete user-controllable data in data storage systems, or that submit user test responses, at least one of the following is true:

Content/Design Considerations

Frames & iFrames

4.1.2 Name, Role, Value

For all user interface components (including but not limited to: form elements, links and components generated by scripts), the name and role can be programmatically determined; states, properties, and values that can be set by the user can be programmatically set; and notification of changes to these items is available to user agents, including assistive technologies. (Level A)

Frames that contain repetitive content can be used to meet 2.4.1, however, frames are obsolete in HTML5.

2.4.1 Bypass Blocks

A mechanism is available to bypass blocks of content that are repeated on multiple web pages. (Level A)

Development Considerations

Headings

2.4.6 Headings and Labels

Headings and labels describe topic or purpose. (Level AA).

Refer to WebAIM’s Using Headings for Content Structure.

Content/Design Considerations

1.3.1 Info and Relationships

Information, structure, and relationships conveyed through presentation can be programmatically determined or are available in text. (Level A)

Development Considerations

Images

1.1.1 Non-Text Content - Meaningful Images

All non-text content that is presented to the user has a text alternative that serves the equivalent purpose.

Content owners are the best resource for text descriptions since they know what information they want the image to convey. Determine alt text by asking, “What text would I put here instead of this picture?”

Content/Design Considerations

Development Considerations

1.1.1 Non-Text Content - Decorative Images

All non-text content that is presented to the user should have a text alternative that serves the equivalent purpose; since decorative images do not convey any meaning for any user, they should include a blank alt tag.

Content/Design Considerations

Development Considerations

1.4.5 Images of Text

If the technologies being used can achieve the visual presentation, text is used to convey information rather than images of text.

Avoid using images of text. Use text instead.

4.1.2 Name, Role, Value

For all user interface components (including but not limited to: form elements; links; and components generated by scripts), the name and role can be programmatically determined; states, properties, and values that can be set by the user can be programmatically set; and notification of changes to these items is available to user agents, including assistive technologies.

Content/Design Considerations

Development Considerations

Keyboard and Focus

2.1.1 Keyboard

All functionality of the content is operable through a keyboard interface without requiring specific timings for individual keystrokes, except where the underlying function requires input that depends on the path of the user’s movement and not just the endpoints.

Development Considerations

2.1.2 No Keyboard Trap

If keyboard focus can be moved to a component of the page using a keyboard interface, then focus can be moved away from that component using only a keyboard interface, and, if it requires more than unmodified arrow or tab keys or other standard exit methods, the user is advised of the method for moving focus away.

Failure to meet this requirement could interfere with any use of the page. Refer to Requirement 5 - Non-Interference to learn more.

Development Considerations

2.4.7 Focus Visible

Any keyboard operable user interface has a mode of operation where the keyboard focus indicator is visible.

Development Considerations

2.4.3 Focus Order

If a web page can be navigated sequentially and the navigation sequences affect meaning or operation, focusable components receive focus in an order that preserves meaning and operability.

Development Considerations

3.2.1 On Focus

When any component receives focus, it does not initiate a change of context.

Content/Design Considerations

Development Considerations

Don’t use javascript to perform a function that changes the page’s context on the focus event (onfocus).

Language

3.1.1 Language of Page

The default human language of each web page can be programmatically determined.

Development Considerations
Identify the default lang attribute on the HTML element:

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>WAI application shell</title>
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <link rel="stylesheet" type="text/css" href="styles/style.css">
</head>

Review list of lang values.

3.1.2 Language of Parts

The human language of each passage or phrase in the content can be programmatically determined except for proper names, technical terms, words of indeterminate language, and words or phrases that have become part of the vernacular of the immediately surrounding text.

Content/Design Considerations

Development Considerations

The purpose of each link can be determined from the link text alone, or from the link text together with its programmatically determined link context, except where the purpose of the link would be ambiguous to users in general.

Best Practice: Although the requirement allows for it, avoid vague link text like “click here” and “read more”. Avoid using the same link text for links that have different destinations.

This requirement covers both links and buttons.

Content/Design Considerations

Development Considerations

Multiple Ways

2.4.5 Multiple Ways

More than one way is available to locate a web page within a set of web pages except where the web page is the result of, or a step in, a process.

Content/Design Considerations

Page Title

2.4.2 Page Titled

Web pages have titles that describe topic or purpose.

Content/Design Considerations

Development Considerations

    <!DOCTYPE html>  
    <html>  
    <head>  
    <meta charset="utf-8">  
    **<title>WAI help for page title</title>**  
    <link rel="manifest" href="/manifest.json">  
    <meta http-equiv="X-UA-Compatible" content="IE=edge">  
    <meta name="viewport" content="width=device-width, initial-scale=1.0">  
    <link rel="stylesheet" type="text/css" href="styles/style.css">  
    </head>
    

Parsing

4.1.1 Parsing

In content implemented using markup languages, elements have complete start and end tags, elements are nested according to their specifications, elements do not contain duplicate attributes, and any IDs are unique, except where the specifications allow these features.

Note: Start and end tags that are missing a critical character in their formation, such as a closing angle bracket or a mismatched attribute value quotation mark are not complete.

Development Considerations

Repetitive Content

2.4.1 Bypass Blocks

A mechanism is available to bypass blocks of content that are repeated on multiple web pages.

Content/Design Considerations

Development Considerations

3.2.3 Consistent Navigation

Navigational mechanisms that are repeated on multiple web pages within a set of web pages occur in the same relative order each time they are repeated, unless a change is initiated by the user.

Content/Design Considerations

Development Considerations

3.2.4 Consistent Identification

Components that have the same functionality within a set of web pages are identified consistently.

Content/Design Considerations

Development Considerations

Resizable Text

1.4.4 Resize Text

Except for captions and images of text, text can be resized without assistive technology up to 200 percent without loss of content or functionality.

Development Considerations

Sensory Characteristics

1.3.3 Sensory Characteristics

Instructions provided for understanding and operating content do not rely solely on sensory characteristics of components such as shape, size, visual location, orientation, or sound.

Content/Design Considerations

1.4.1 Use of Color

Color is not used as the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element.

Content/Design Considerations

Stylesheet

1.1.1 Non-Text Content

All non-text content that is presented to the user has a text alternative that serves the equivalent purpose.

Content/Design Considerations

Development Considerations

1.3.1 Info and Relationships

Information, structure, and relationships conveyed through presentation can be programmatically determined or are available in text.

Development Considerations

1.3.2 Meaningful Sequence

When the sequence in which content is presented affects its meaning, a correct reading sequence can be programmatically determined.

Development Considerations

Synchronized Media

1.2.2 Captions (Prerecorded)

Captions are provided for all prerecorded audio content in synchronized media, except when the media is a media alternative for text and is clearly labeled as such.

Content/Design Considerations

Development Considerations

1.2.3 Audio Description or Media Alternative (Prerecorded)

An alternative for time-based media or audio description of the prerecorded video content is provided for synchronized media, except when the media is a media alternative for text and is clearly labeled as such.

**Please see 1.2.5 (below) for Section 508 conformance guidance, which requires audio description.**

1.2.4 Captions (Live)

Captions are provided for all live audio content in synchronized media.

Content/Design Considerations

Development Considerations

1.2.5 Audio Description (Prerecorded)

Audio description is provided for all prerecorded video content in synchronized media.

Content/Design Considerations

Development Considerations

1.4.2 Audio Control

If any audio on a web page plays automatically for more than 3 seconds, either a mechanism is available to pause or stop the audio, or a mechanism is available to control audio volume independently from the overall system volume level.

Failure to meet this requirement could interfere with any use of the page. Refer to Requirement 5 - Non-Interference to learn more.

Content/Design Considerations

Development Considerations

2.2.2 Pause, Stop, Hide

For moving, blinking, scrolling, or auto-updating information, ALL of the following are true:

Failure to meet this requirement could interfere with any use of the page. Refer to Requirement 5 - Non-Interference to learn more.

Content/Design Considerations

Section 508 Requirements for Synchronized Media

503.4 User Controls for Captions and Audio Description.

Where ICT displays video with synchronized audio, ICT shall provide user controls for closed captions and audio descriptions.

503.4.1 Caption Controls.

Where user controls are provided for volume adjustment, ICT shall provide user controls for the selection of captions at the same menu level as the user controls for volume or program selection.

503.4.2 Audio Description Controls.

Where user controls are provided for program selection, ICT shall provide user controls for the selection of audio descriptions at the same menu level as the user controls for volume or program selection.

Content/Design Considerations

Development Considerations

Tables

1.3.1 Info and Relationships

Information, structure, and relationships conveyed through presentation can be programmatically determined or are available in text.

Content/Design Considerations

Development Considerations

    <table>
      <caption>Bordered table</caption>
      <thead>
        <tr>
          <th scope="col">Document title</th>
          <th scope="col">Description</th>
          <th scope="col">Year</th>
        </tr>
      </thead>
      <tbody>
        <tr>
          <th scope="row">Declaration of Independence</th>
          <td>Statement adopted by the Continental Congress declaring independence from the British Empire.</td>
          <td>1776</td>
        </tr>
        <tr>
          <th scope="row">Bill of Rights</th>
          <td>The first ten amendments of the U.S. Constitution guaranteeing rights and freedoms.</td>
          <td>1791</td>
        </tr>
        </tbody>
    </table>
    

Timed Events

2.2.1 Timing Adjustable

For each time limit that is set by the content, at least ONE of the following is true:

Content/Design Considerations

2.2.2 Pause, Stop, Hide

For moving, blinking, scrolling, or auto-updating information, ALL of the following are true:

Failure to meet this requirement could interfere with any use of the page. Refer to Requirement 5 - Non-Interference to learn more.

Content/Design Considerations

1.4.2 Audio Control

If any audio on a web page plays automatically for more than 3 seconds, either a mechanism is available to pause or stop the audio, or a mechanism is available to control audio volume independently from the overall system volume level.

Failure to meet this requirement could interfere with any use of the page. Refer to Requirement 5 - Non-Interference to learn more.

Content/Design Considerations

Development Considerations

WCAG Conformance Requirements

Requirement 1: Alternate Pages

Development Considerations

To meet the requirements of a conforming alternate version, it must:

  1. Conform to all Level A and AA criteria, and
  2. Provide all of the same information and functionality in the same human language, and
  3. Be as up to date as the non-conforming content, and
  4. At least one of the following is true:
    1. The conforming version can be reached from the non-conforming page via an accessibility-supported mechanism, or
    2. The non-conforming version can only be reached from the conforming version, or
    3. The non-conforming version can only be reached from a conforming page that also provides a mechanism to reach the conforming version.

Note 1: In this definition, “can only be reached” means that there is some mechanism, such as a conditional redirect, that prevents a user from “reaching” (loading) the non-conforming page unless the user had just come from the conforming version.

Note 2: The alternate version does not need to be matched page for page with the original (e.g., the conforming alternate version may consist of multiple pages).

Note 3: If multiple language versions are available, then conforming alternate versions are required for each language offered.

Note 4: Alternate versions may be provided to accommodate different technology environments or user groups. Each version should be as conformant as possible. One version would need to be fully conformant in order to meet conformance requirement 1.

Note 5: The conforming alternative version does not need to reside within the scope of conformance, or even on the same website, as long as it is as freely available as the non-conforming version.

Note 6: Alternate versions should not be confused with supplemental content, which support the original page and enhance comprehension.

Note 7: Setting user preferences within the content to produce a conforming version is an acceptable mechanism for reaching another version as long as the method used to set the preferences is accessibility supported.

See Understanding Conforming Alternate Versions.

Requirement 2: Full pages

Conformance (and conformance level) is for full web page(s) only, and cannot be achieved if part of a web page is excluded.

Note 1: For the purpose of determining conformance, alternatives to part of a page’s content are considered part of the page when the alternatives can be obtained directly from the page, e.g., a long description or an alternative presentation of a video.

Note 2: Authors of web pages that cannot conform due to content outside of the author’s control may consider a Statement of Partial Conformance.

Requirement 3: Complete processes

When a web page is one of a series of web pages presenting a process (i.e., a sequence of steps that need to be completed in order to accomplish an activity), all web pages in the process conform at the specified level or better. (Conformance is not possible at a particular level if any page in the process does not conform at that level or better.)

Example: An online store has a series of pages that are used to select and purchase products. All pages in the series from start to finish (checkout) conform in order for any page that is part of the process to conform.

Requirement 4: Only Accessibility-Supported Ways of Using Technologies

Only accessibility-supported ways of using technologies are relied upon to satisfy the success criteria. Any information or functionality that is provided in a way that is not accessibility supported is also available in a way that is accessibility supported. (See Understanding accessibility support.)

Requirement 5: Non-Interference

If technologies are used in a way that is not accessibility supported, or if they are used in a non-conforming way, then they do not block the ability of users to access the rest of the page. In addition, the web page as a whole continues to meet the conformance requirements under each of the following conditions:

  1. When any technology that is not relied upon is turned on in a user agent,
  2. When any technology that is not relied upon is turned off in a user agent, and
  3. When any technology that is not relied upon is not supported by a user agent

In addition, the following success criteria apply to all content on the page, including content that is not otherwise relied upon to meet conformance, because failure to meet them could interfere with any use of the page:

Other Resources

Created by the CIO Council’s Accessibility Community of Practice, this information is presented in categories that align to the Baseline Tests for Revised 508 Standards, which cover all WCAG 2.0 Level A and AA requirements, and will be the basis of the updated Trusted Tester Test Process.

Reviewed/Updated: January 2023

Section508.gov

An official website of the General Services Administration

Looking for U.S. government information and services?
Visit USA.gov