WCAG 2.1 Reference

Below is the list of WCAG 2.1 requirements for digital accessibility. This list covers level A and AA requirements. AAA, the highest rating, is not included because it’s not a legal requirement yet. Included below are the exact WCAG requirements, notes on how the scan will help, and helpful tips.

Click Here to see the complete WCAG 2.1 checklist and guide: WCAG 2.1 Quick Reference Guide on the Web Accessibility Initiative (WAI) homepage

Information and user interface components must be presentable to users in ways they can perceive.

Guideline 1.1 – Text Alternatives

Provide text alternatives for any non-text content so that it can be changed into other forms people need, such as large print, braille, speech, symbols or simpler language.

1.1.1 Non-text Content Level A

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

Tip: Non-text files such as images or PDFs need to have plain-english alt text descriptions that describe the contents of the image.

Guideline 1.2 – Time-based Media

Provide alternatives for time-based media.

1.2.1 Audio-only and Video-only (Prerecorded) Level A

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:

  • Prerecorded Audio-only: An alternative for time-based media is provided that presents equivalent information for prerecorded audio-only content.
  • Prerecorded Video-only: Either an alternative for time-based media or an audio track is provided that presents equivalent information for prerecorded video-only content

Tip: If video or audio is presented on your site, you need to present a text alternative, such as a transcript.

1.2.2 Captions (Prerecorded) Level A

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.

Tip: Synchronized media, such as a video with audio (YouTube video is a good example) needs captions displayed as part of the media file.

1.2.3 Audio Description or Media Alternative (Prerecorded) Level A

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.

Tip: Synchronized media, such as a video with audio (YouTube video is a good example) needs captions displayed as part of the media file.

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

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.

Tip: If you’re displaying live video or audio, you need captions enabled (likely, this will be something to confirm through your 3rd-party media provider, such as LiveStream or your Webinar software)

1.2.5 Audio Description (Prerecorded) Level AA

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

Guideline 1.3 – Adaptable

Create content that can be presented in different ways (for example simpler layout) without losing information or structure.

1.3.1 Info and Relationships Level A

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

1.3.2 Meaningful Sequence Level A

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

Tip: If you’re displaying live video or audio, you need captions enabled (likely, this will be something to confirm through your 3rd-party media provider, such as LiveStream or your Webinar software)

1.3.3 Sensory Characteristics Level A

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.

Tip: You can’t have an instruction on the website that refers to a sensory characteristic as the only way to identify something. For example, the text “Click on the round button to submit your application” wouldn’t be compliant, because the instruction refers only to a sensory characteristic, in this case a ‘round’ button, which would be indistinguishable to a blind person.

1.3.4 Orientation Level AA

Content does not restrict its view and operation to a single display orientation, such as portrait or landscape, unless a specific display orientation is essential.

1.3.5 Identify input Purpose Level AA

The purpose of each input field collecting information about the user can be programmatically determined when:

  • The input field serves a purpose identified in the Input Purposes for User Interface Components section; and
  • The content is implemented using technologies with support for identifying the expected meaning for form input data.

Tip: Check the purpose of the input against the list here and if the purpose for the input is on the list, then make sure the input has the attribute “autocomplete” with the corresponding value from the list, i.e. autocomplete=”email”.

Guideline 1.4 – Distinguishable

Make it easier for users to see and hear content including separating foreground from background.

1.4.1 Use of Color Level A

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

Tip: A reference to color can’t be the only way to distinguish something. For example, the text “Click on the green button to submit your application” wouldn’t be compliant, because the instruction refers only to the color green, which would be indistinguishable to a blind person.

1.4.2 Audio Control Level A

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.

Tip: As a general best practice outside of accessibility compliance, you shouldn’t have any audio auto-playing. It’s a conversion killer. But if you do, you need a mechanism to be able to pause or stop the audio, and it needs to be navigable via keyboard.

1.4.3 Contrast (Minimum) Level AA

The visual presentation of text and images of text has a contrast ratio of at least 4.5:1, except for the following:
  • Large Text: Large-scale text and images of large-scale text have a contrast ratio of at least 3:1.
  • Incidental: Text or images of text that are part of an inactive user interface component, that are pure decoration, that are not visible to anyone, or that are part of a picture that contains significant other visual content, have no contrast requirement.
  • Logotypes: Text that is part of a logo or brand name has no minimum contrast requirement.

Tip: As a general best practice outside of accessibility compliance, you shouldn’t have any audio auto-playing. It’s a conversion killer. But if you do, you need a mechanism to be able to pause or stop the audio, and it needs to be navigable via keyboard.

1.4.4 Resize text Level AA

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

Tip: We interpret that you’ll meet accessibility compliance as long as your screen can be zoomed in up to 200% by using your keyboard (on PCs, it’s CTRL and +) without losing site function.

1.4.5 Resize text Level AA

If the technologies being used can achieve the visual presentation, text is used to convey information rather than images of text except for the following:
  • Customizable: The image of text can be visually customized to the user’s requirements.
  • Essential: A particular presentation of text is essential to the information being conveyed.

Tip: Don’t bake text into an image file, because blind people can’t read text that’s saved as part of an image file. Logos are exempt from this, but your logo image file should have clear alt text that describes any text that is part of the logo.

1.4.10 Reflow Level AA

Content can be presented without loss of information or functionality, and without requiring scrolling in two dimensions for:

  • User Interface Components: Visual information required to identify user interface components and states, except for inactive components or where the appearance of the component is determined by the user agent and not modified by the author;
  • Graphical Objects: Parts of graphics required to understand the content, except when a particular presentation of graphics is essential to the information being conveyed.

1.4.11 Non-text Contrast Level AA

The visual presentation of the following have a contrast ratio of at least 3:1 against adjacent color(s):

  • Vertical scrolling content at a width equivalent to 320 CSS pixels;
  • Horizontal scrolling content at a height equivalent to 256 CSS pixels;
    Except for parts of the content which require two-dimensional layout for usage or meaning.

1.4.12 Text Spacing Level AA

In content implemented using markup languages that support the following text style properties, no loss of content or functionality occurs by setting all of the following and by changing no other style property:
  • Line height (line spacing) to at least 1.5 times the font size;
  • Spacing following paragraphs to at least 2 times the font size;
  • Letter spacing (tracking) to at least 0.12 times the font size;
  • Word spacing to at least 0.16 times the font size.
Exception: Human languages and scripts that do not make use of one or more of these text style properties in written text can conform using only the properties that exist for that combination of language and script.

1.4.13 Content on Hover or Focus Level AA

Where receiving and then removing pointer hover or keyboard focus triggers additional content to become visible and then hidden, the following are true:
  • Dismissible: A mechanism is available to dismiss the additional content without moving pointer hover or keyboard focus, unless the additional content communicates an input error or does not obscure or replace other content;
  • Hoverable: If pointer hover can trigger the additional content, then the pointer can be moved over the additional content without the additional content disappearing;
  • Persistent: The additional content remains visible until the hover or focus trigger is removed, the user dismisses it, or its information is no longer valid.
Exception: The visual presentation of the additional content is controlled by the user agent and is not modified by the author.

User interface components and navigation must be operable.

Guideline 2.1 – Keyboard Accessible

Provide text alternatives for any non-text content so that it can be changed into other forms people need, such as large print, braille, speech, symbols or simpler language.

2.1.1 Keyboard Level A

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.

Tip: Your site needs to be navigable and functional by keyboard alone, meaning the user needs to be able to “tab” through all size pages, menus, buttons and forms, etc… And clicking “enter” submits anything that requires submission.

2.1.2 No Keyboard Trap Level A

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.

2.1.4 Character Key Shortcuts Level A

If a keyboard shortcut is implemented in content using only letter (including upper- and lower-case letters), punctuation, number, or symbol characters, then at least one of the following is true:
  • Turn off: A mechanism is available to turn the shortcut off;
  • Remap: A mechanism is available to remap the shortcut to include one or more non-printable keyboard keys (e.g., Ctrl, Alt);
  • Active only on focus: The keyboard shortcut for a user interface component is only active when that component has focus.

Guideline 2.2 – Enough Time

Provide users enough time to read and use content.

2.2.1 Timing Adjustable Level A

For each time limit that is set by the content, at least one of the following is true:
  • Turn off: The user is allowed to turn off the time limit before encountering it, or
  • Adjust: The user is allowed to adjust the time limit before encountering it over a wide range that is at least ten times the length of the default setting, or
  • Extend: The user is warned before time expires and given at least 20 seconds to extend the time limit with a simple action (for example, ‘press the space bar’), and the user is allowed to extend the time limit at least ten times, or
  • Real-time Exception: The time limit is a required part of a real-time event (for example, an auction), and no alternative to the time limit is possible, or
  • Essential Exception: The time limit is essential and extending it would invalidate the activity, or
  • 20 Hour Exception: The time limit is longer than 20 hours.

2.2.2 Pause, Stop, Hide Level A

For moving, blinking, scrolling, or auto-updating information, all of the following are true:
  • Moving, blinking, scrolling: For any moving, blinking or scrolling information that (1) starts automatically, (2) lasts more than five seconds, and (3) is presented in parallel with other content, there is a mechanism for the user to pause, stop, or hide it unless the movement, blinking, or scrolling is part of an activity where it is essential, and
  • Auto-updating: For any auto-updating information that (1) starts automatically and (2) is presented in parallel with other content, there is a mechanism for the user to pause, stop, or hide it or to control the frequency of the update unless the auto-updating is part of an activity where it is essential.

Guideline 2.3 – Seizures

Do not design content in a way that is known to cause seizures

2.3.1 Three Flashes or Below Threshold Level A

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.

Guideline 2.4 – Navigable

Provide ways to help users navigate, find content, and determine where they are.

2.4.1 Bypass Blocks Level A

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

Tip: Example: An online newspaper’s homepage might have a main story, 15 other stories, and 10 advertisements, which might total dozens of links and buttons, which would otherwise take a screen reader or keyboard a very long time to “tab” through and audibly read. You’ll need a link at the top of the page that says “jump to main story”, thus saving a blind person a lot of wasted time.

2.4.2 Page Titled Level A

Web pages have titles that describe topic or purpose.

2.4.3 Focus Order Level A

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.

Tip: The order in which someone navigates from action/link to action/link needs to be in a logical order. In other words, “tabbing” through a webpage can’t result in nonsensical jumping around. Things must be in logical order.

2.4.4 Link Purpose (In Context) Level A

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.

Tip: A link shouldn’t just say “click here”, or “link”. The text of the link should be descriptive to the contents of the link. Example: “There was much bloodshed during the Medieval period of history”, and “Medieval Period” is the link.

2.4.5 Multiple Ways Level AA

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.

Tip: You need to have more than one way to access a webpage. For example, the website’s main navigation menu represents one way to access a page. A second way to access a page would be having inter-linking between pages, or a secondary menu (like a sidebar menu, for example).

2.4.6 Headings and Labels Level AA

Headings and labels describe topic or purpose.

Tip: This task permeates much of the site. Pages need to have proper headings to identify site content, and in the right order (H2 tags shouldn’t be in front of H1 tags, etc…). Also, embedded tables, objects, iFrames, YouTube videos, etc… all need to have proper headings. Assume that these heading tags won’t be provided by the embed code. You’ll need add them manually via HTML manipulation.

2.4.7 Focus Visible Level AA

Any keyboard operable user interface has a mode of operation where the keyboard focus indicator is visible.
Tip: As someone “tabs” through the website, there needs to be a visible cue as to where the cursor is at, and it needs to meet the 4.5:1 color contrast ratio. An example would be underlining words/links, or illuminating buttons.

Guideline 2.5 – Input Modalities

Provide ways to help users navigate, find content, and determine where they are.

2.5.1 Pointer Gestures Level A

All functionality that uses multipoint or path-based gestures for operation can be operated with a single pointer without a path-based gesture, unless a multipoint or path-based gesture is essential.

2.5.2 Pointer Cancellation Level A

For functionality that can be operated using a single pointer, at least one of the following is true:
  • No Down-Event: The down-event of the pointer is not used to execute any part of the function;
  • Abort or Undo: Completion of the function is on the up-event, and a mechanism is available to abort the function before completion or to undo the function after completion;
  • Up Reversal: The up-event reverses any outcome of the preceding down-event;
  • Essential: Completing the function on the down-event is essential.

2.5.3 Label in Name Level A

For user interface components with labels that include text or images of text, the name contains the text that is presented visually.

2.5.4 Motion Actuation Level A

Functionality that can be operated by device motion or user motion can also be operated by user interface components and responding to the motion can be disabled to prevent accidental actuation, except when:
  • Supported Interface: The motion is used to operate functionality through an accessibility supported interface;
  • Essential: The motion is essential for the function and doing so would invalidate the activity.

Information and the operation of user interface must be understandable.

Guideline 3.1 – Readable

Make text content readable and understandable.

3.1.1 Language of Page Level A

The default human language of each Web page can be programmatically determined.
Tip: A lang attribute on the HTML element needs to be present.

3.1.2 Language of Parts Level AA

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.

Guideline 3.2 – Predictable

Make Web pages appear and operate in predictable ways.

3.2.1 On Focus Level A

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

3.2.2 On Input Level A

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.

3.2.3 Consistent Navigation Level AA

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.

3.2.4 Consistent Identification Level AA

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

Guideline 3.3 – Input Assistance

Help users avoid and correct mistakes.

3.3.1 Error Identification Level A

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.
Tip: This is common in forms. If someone enters incorrect data or skips a required field, a plain-text message or alert appears, letting the user know what to fix.

3.3.2 Labels or Instructions Level A

Labels or instructions are provided when content requires user input.
Tip: Form fields need titles that describe what’s required of them.

3.3.3 Error Suggestion Level AA

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.

3.3.4 Error Prevention (Legal, Financial, Data) Level AA

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:
  • Reversible: Submissions are reversible.
  • Checked: Data entered by the user is checked for input errors and the user is provided an opportunity to correct them.
  • Confirmed: A mechanism is available for reviewing, confirming, and correcting information before finalizing the submission.

Content must be robust enough that it can be interpreted reliably by a wide variety of user agents, including assistive technologies.

Guideline 4.1 – Compatible

Maximize compatibility with current and future user agents, including assistive technologies.

4.1.1 Parsing Level A

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.

4.1.2 Name, Role, Value Level A

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.

4.1.3 Status Messages AA

In content implemented using markup languages, status messages can be programmatically determined through role or properties such that they can be presented to the user by assistive technologies without receiving focus.