Website accessibility

It is recommended that government departments conform to at least Level A of the W3C's Web Content Accessibility Guidelines (WCAG) 2.1.

Level A is the lowest conformance level. It includes the most basic web accessibility features, addressing the most critical barriers to accessing content. Meeting Level A ensures that a website is minimally accessible to users with disabilities.

The following website accessibility standards are the Level A guidelines from the W3C as updated in December 2024.

1. Perceivable

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

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

All non-text content - any content that is not a sequence of characters that can be programmatically determined or where the sequence is not expressing something in human language - that is presented to the user has a text alternative that serves the equivalent purpose, except for the situations listed below.

Controls, input: If non-text content is a control or accepts user input, then it has a name that describes its purpose. (Refer to 4.1.2 for additional requirements for controls and content that accepts user input.)
Time-based media: If non-text content is time-based media, then text alternatives at least provide descriptive identification of the non-text content. (Refer to Guideline 1.2 for additional requirements for media.)
Test: If non-text content is a test or exercise that would be invalid if presented in text, then text alternatives at least provide descriptive identification of the non-text content.
Sensory: If non-text content is primarily intended to create a specific sensory experience, then text alternatives at least provide descriptive identification of the non-text content.
CAPTCHA: If the purpose of non-text content is to confirm that 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.
Decoration, formatting, invisible: If non-text content is pure decoration, is used only for visual formatting, or is not presented to users, then it is implemented in a way that it can be ignored by assistive technology.

1.2 Time-based media

Provide alternatives for time-based media.

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 labelled 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.

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 labelled as such.

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 labelled as such.

1.3 Adaptable

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

1.3.1 Information and relationships

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

1.3.2 Meaningful sequence

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

1.3.3 Sensory characteristics

Instructions provided for understanding and operating content do not rely solely on sensory characteristics of components such as shape, colour, size, visual location, orientation, or sound. (For requirements related to colour, refer to Guideline 1.4.)

1.4 Distinguishable

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

1.4.1 Use of colour

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

This addresses colour perception specifically. Other forms of perception are covered in Guideline 1.3 including programmatic access to colour and other visual presentation coding.)

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.

Since any content that does not meet this can interfere with a user's ability to use the whole page, all content on the Web page (whether or not it is used to meet other success criteria) must meet this success criterion. See Conformance Requirement 5: Non-Interference.

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:

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 contrast requirement.

2. Operable

User interface components and navigation must be operable.

2.1 Keyboard Accessible

Make all functionality available from a keyboard.

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.

This exception relates to the underlying function, not the input technique. For example, if using handwriting to enter text, the input technique (handwriting) requires path-dependent input, but the underlying function (text input) does not.

This does not forbid and should not discourage providing mouse input or other input methods in addition to keyboard operation.

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.

Since any content that does not meet this can interfere with a user's ability to use the whole page, all content on the Web page (whether it is used to meet other success criteria or not) must meet this success criterion. See Conformance Requirement 5: Non-Interference.

2.1.4 Character key shortcuts

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.

2.2 Enough time

Provide users enough time to read and use content.

2.2.1 Timing adjustable

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.

This helps ensure that users can complete tasks without unexpected changes in content or context that are a result of a time limit. This should be considered in conjunction with 3.2.1, which puts limits on changes of content or context as a result of user action.

2.2.2 Pause, stop, hide

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.

For requirements related to flickering or flashing content, refer to Guideline 2.3.

Content that is updated periodically by software or that is streamed to the user agent is not required to preserve or present information that is generated or received between the initiation of the pause and resuming presentation, as this may not be technically possible, and in many situations could be misleading to do so.

An animation that occurs as part of a preload phase or similar situation can be considered essential if interaction cannot occur during that phase for all users and if not indicating progress could confuse users or cause them to think that content was frozen or broken.

2.3 Seizures and physical reactions

Do not design content in a way that is known to cause seizures or physical reactions.

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.

2.4 Navigable

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

2.4.1 Bypass blocks

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

2.4.2 Page titled

Web pages have titles that describe topic or purpose.

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.

2.4.4 Link purpose (in context)

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.

2.5 Input modalities

Make it easier for users to operate functionality through various inputs beyond keyboard.

2.5.1 Pointer gestures

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.

This requirement applies to web content that interprets pointer actions (i.e. this does not apply to actions that are required to operate the user agent or assistive technology).

2.5.2 Pointer cancellation

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.

Functions that emulate a keyboard or numeric keypad key press are considered essential.

This requirement applies to web content that interprets pointer actions (i.e. this does not apply to actions that are required to operate the user agent or assistive technology).

2.5.3 Label in name

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

A best practice is to have the text of the label at the start of the name.

2.5.4 Motion actuation

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.

2.5.6 Concurrent input mechanisms

Web content does not restrict use of input modalities available on a platform except where the restriction is essential, required to ensure the security of the content, or required to respect user settings.

3. Understandable

Information and the operation of the user interface must be understandable.

3.1 Readable

Make text content readable and understandable.

3.1.1 Language of page

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

3.2 Predictable

Make web pages appear and operate in predictable ways.

3.2.1 On focus

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

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 behaviour before using the component.

3.3 Input assistance

Help users avoid and correct mistakes.

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.

3.3.2 Labels or instructions

Labels or instructions are provided when content requires user input.

4. Robust

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

4.1 Compatible

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

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.

This should be considered as always satisfied for any content using HTML or XML.

Since this criterion was written, the HTML Living Standard has adopted specific requirements governing how user agents must handle incomplete tags, incorrect element nesting, duplicate attributes, and non-unique IDs. [HTML]

Although the HTML standard treats some of these cases as non-conforming for authors, it is considered to "allow these features" for the purposes of this because the specification requires that user agents support handling these cases consistently. In practice, this criterion no longer provides any benefit to people with disabilities in itself.

Issues such as missing roles due to inappropriately nested elements or incorrect states or names due to a duplicate ID are covered by different success criteria and should be reported under those criteria rather than as issues with 4.1.1.

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.

This is primarily for Web authors who develop or script their own user interface components. For example, standard HTML controls already meet this when used according to specification.

Source: Web Content Accessibility Guidelines (WCAG) 2.1