Accessibility is a core part of digital performance. Websites that meet accessibility standards create better experiences for users with disabilities, improve usability for everyone, and support compliance with legal obligations. The Web Content Accessibility Guidelines (WCAG) are the international benchmark for digital accessibility. Developed by the World Wide Web Consortium (W3C), these guidelines help organisations ensure that their websites are usable for people with a range of impairments, including vision, hearing, motor, and cognitive limitations.WCAG has several versions, including 2.0, 2.1, and the most recent 2.2. Each version builds on the last and introduces new success criteria. The guidelines also include levels of conformance—A, AA, and AAA—that define how thoroughly a website meets accessibility requirements.

The idea of web accessibility doesn’t get too much attention when discussing web design and development. Yet, it is one of the key factors in providing a great user experience. Unlike UI/UX design or website hosting and support, it’s often the last thing we think about and even take for granted.

This guide explains how WCAG works, what each version includes, and how organisations can move toward compliance. It also outlines practical steps for improving accessibility across websites and digital content.

Internal audits, accessibility tools, and expert testing all help meet WCAG requirements. If your organisation plans a new website or reviews an existing one, this information will help you understand the applicable standards.

What Are WCAG Guidelines?

The Web Content Accessibility Guidelines (WCAG) are a global technical standard that evaluates whether websites and digital platforms are accessible to people with disabilities. They are produced by the World Wide Web Consortium (W3C), and most government policies and tenders reference them as the required benchmark.

In practice, WCAG functions as both a design and development guide and a compliance framework. It outlines measurable success criteria that can be tested using tools, audits, and manual reviews. The guidelines are divided into conformance levels—A, AA, and AAA—and each level introduces stricter requirements.

Most organisations aiming to meet accessibility obligations target WCAG 2.1 Level AA. This level is considered the practical standard for public websites, balancing scope with feasibility. It includes requirements such as sufficient colour contrast, keyboard operability, alternative text, and clear navigation structures.

Although WCAG is often framed as a checklist, it is more accurately used as a shared language between marketers, developers, designers, and procurement teams. Understanding which version and conformance level applies to your organisation is essential, particularly when planning a redevelopment or engaging a new vendor.

To see how Australian regulations align with WCAG, visit our blog on website accessibility standards in Australia.

The POUR Principles of Web Accessibility

At the core of WCAG are four foundational principles: Perceivable, Operable, Understandable, and Robust. These are known collectively as the POUR principles. They form the conceptual framework behind all the success criteria outlined in WCAG 2.0, 2.1, and 2.2.

Understanding POUR helps teams avoid treating accessibility as a technical add-on. It shifts the focus to user experience, especially for users who interact with content differently due to disability or assistive technology.

Perceivable means that users must be able to perceive the content. This includes text alternatives for images, captions for video, and readable typography. If content isn’t perceivable, it doesn’t exist for many users.

Operable refers to interaction. Users should be able to navigate using a keyboard, pause or skip time-based media, and avoid content that triggers seizures or physical discomfort.

Understandable relates to clarity. Content must be readable, predictable, and forgiving. That includes consistent navigation, helpful error messages, and forms that don’t confuse the user.

Robust means content must work with current and future technologies, including assistive tech like screen readers. It also includes properly structured code that machines and browsers can interpret.

POUR is a helpful filter for reviewing designs, evaluating features, and planning accessibility work in real projects.

Assistive Technologies That Support Web Accessibility

Assistive technologies are tools or software used by people with disabilities to access digital content. These technologies are critical in how users interact with websites and applications, especially when traditional interfaces are unusable.

WCAG guidelines are designed with these technologies in mind. Many of the success criteria directly support or enable compatibility with assistive tools. For example, ensuring proper heading structure, labelling, and keyboard operability helps screen readers and alternative navigation tools work as intended.

Here are some standard assistive technologies relevant to web accessibility:

Captioning and Transcription Services

Transcription services help individuals with hearing impairments or those who can’t understand different languages. These services provide text options for video and audio content.

Text-to-Speech Software

These tools convert on-screen text into speech, and they are used by individuals with learning disabilities or visual impairments. WCAG criteria like readable content, clear hierarchy, and contrast directly improve these experiences.

Screen Readers

Software like NVDA, JAWS, and VoiceOver reads out the content of a webpage. They interpret HTML elements such as headings, lists, alt text, and form labels. Properly structured and coded websites provide a better experience for screen reader users.

Magnification and Zoom Tools

Low vision users rely on screen magnifiers or browser zoom features. Sites that use responsive design and scalable layouts perform better under these conditions.

Speech Recognition Software

Tools like Dragon Naturally Speaking allow users to control a computer or fill in forms using voice commands. Proper labelling and predictable interaction patterns improve compatibility.

Keyboard Navigation Tools

Some users navigate entirely by keyboard or alternative input devices. All interactive elements—including menus, buttons, modals, and forms—must be accessible without a mouse.

WCAG Versions Explained: 2.0 vs 2.1 vs 2.2

The WCAG guidelines have evolved to respond to changes in technology and user needs. Each version builds on the previous one and introduces additional criteria for improving accessibility. While WCAG 2.0 remains the legal reference point in many regions, most organisations today aim to meet WCAG 2.1, and there is growing interest in the newly released WCAG 2.2.

WCAG 2.0

WCAG 2.0 was released in 2008 and remains the reference point in many accessibility policies and procurement contracts. It established the four POUR principles and outlined 61 success criteria across three conformance levels (A, AA, AAA).

While WCAG 2.0 provided a strong foundation, it does not address many modern accessibility needs, particularly those related to mobile responsiveness, touch interactions, and users with cognitive impairments.

Organisations still using WCAG 2.0 as their benchmark may meet basic compliance but risk falling short of user expectations and industry best practices.

WCAG 2.1

WCAG 2.1, published in 2018, is now considered the practical minimum for most public-facing websites. It added 17 new success criteria to WCAG 2.0, expanding coverage for mobile device use, low vision, and cognitive accessibility.

Examples of WCAG 2.1 improvements include requirements for:

• Text spacing support
• Input field labelling for autocomplete
• Enhanced keyboard navigation for complex components

Today, most WCAG compliance audits use WCAG 2.1 Level AA as the benchmark. It strikes the right balance between technical feasibility and user benefit, especially for organisations serving the public.

WCAG 2.2

WCAG 2.2 was finalised in October 2023 and introduced nine additional success criteria. These updates improve usability for people with limited dexterity, short-term memory challenges, and attention regulation difficulties.

Notable additions include:

• A requirement for consistent help mechanisms across pages
• Prevention of redundant data entry for returning users
• Stronger focus indicators for navigating by keyboard

Knowing which version you are working toward is critical from a procurement or redesign perspective. Requirements set at WCAG 2.0 may no longer reflect user expectations or regulatory direction. WCAG 2.1 Level AA is the current best-practice benchmark, and WCAG 2.2 is increasingly relevant for forward-looking organisations. 

While WCAG 2.2 is not yet mandated in most policy frameworks, it represents the direction in which accessibility is heading. For new website builds or full-scale redesigns, it makes sense to include WCAG 2.2 in the scope from the outset.

WCAG Compliance Levels: A, AA, and AAA

The WCAG guidelines are structured around three levels of compliance: Level A, Level AA, and Level AAA. Each level adds additional success criteria and increases the accessibility standard that a website or digital product must meet.

Understanding the difference between these levels is essential when setting project scope, vendor expectations, or internal quality benchmarks. The correct target level will depend on your audience, regulatory context, and available resources.

Level A (Minimum Compliance)

This is the baseline. Level A includes success criteria that cover the most critical accessibility failures. A website that meets Level A will address issues such as missing alt text, inaccessible navigation, and lack of keyboard operability.

However, Level A is insufficient for public-facing websites in most sectors. It prevents complete exclusion but does not ensure an equitable experience.

Level AA (Recommended Standard)

Level AA builds on Level A by adding requirements that significantly improve usability for a broader group of users. This includes better colour contrast, predictable navigation, accessible form inputs, and error identification.

WCAG 2.1 Level AA is widely recognised as the appropriate level of compliance for organisations aiming to meet accessibility expectations in education, government, health, and the broader not-for-profit sector.

Most accessibility audits and tender documents nominate this level as the standard.

Level AAA (Maximum Compliance)

Level AAA includes the most advanced and specific requirements. These criteria offer meaningful enhancements for certain user groups but are not considered practical for all content types or website structures.

Some examples include sign language interpretation for video and expanded content clarity standards.

Very few websites meet AAA across the board. AAA is generally reserved for specific use cases where content must be exceptionally accessible—for example, certain health communications or disability support services.

How WCAG Versions Affect Compliance Levels

As explained above, WCAG defines three levels of compliance: Level A, Level AA, and Level AAA. These levels describe the depth of accessibility a website achieves. 

Separately, WCAG also has versions 2.0, 2.1, and 2.2, representing the breadth or scope of the guidelines.

That’s why a common question arises: Is WCAG 2.2 A better than WCAG 2.0 AAA?

The answer depends on what you’re comparing.

The distinction between a version and a compliance level is essential. A higher version introduces new requirements, but each version still uses the same A, AA, and AAA compliance levels. 

Each version of WCAG builds on the previous one by adding new success criteria. Based on their impact and complexity, these new requirements are then grouped into A, AA, or AAA.

• WCAG 2.0 AA includes 38 Level AA criteria.
• WCAG 2.1 AA adds 7 more Level AA criteria on top of 2.0.
• WCAG 2.2 AA includes everything in 2.1 AA plus additional updates that target cognitive and mobile usability.

That means WCAG 2.1 AA is more current and broader in scope than WCAG 2.0 AAA, even if the latter appears stricter on paper.

Similarly, WCAG 2.2 A includes criteria that don’t exist in 2.0 or 2.1 at all. So, even a site meeting Level A under 2.2 may outperform an older AAA site in certain usability areas.

What does this mean in practice?

Most organisations should aim for WCAG 2.1 AA as a minimum. It is the practical, recognised standard in procurement and policy.

WCAG 2.2 AA is emerging as the forward-looking option, especially for new projects or organisations with a strong inclusion mandate.

AAA is not automatically “better”. It should be viewed as a specialised layer—relevant when content serves high-risk or high-sensitivity audiences, or where budgets allow for deeper accessibility investment.

Other Web Accessibility Standards: Section 508, EN 301 549 and More

While WCAG is the global reference point for accessibility, it’s not the only standard in use. Many organisations operate across jurisdictions or participate in tenders that reference alternative or additional frameworks.

Here are some of the most widely recognised accessibility standards that complement or build on WCAG:

Section 508 (United States)

Section 508 is part of the Rehabilitation Act of 1973 in the US. It mandates that federal agencies make electronic and information technology accessible to people with disabilities. In its most recent update, Section 508 directly aligns with WCAG 2.0 Level AA, meaning any content that meets WCAG 2.0 AA also satisfies this standard.

EN 301 549 (European Union)

EN 301 549 is the European accessibility standard. It applies to public sector bodies in the EU and includes requirements for websites, mobile apps, documents, and hardware. Like Section 508, it references WCAG but adds extra clauses for procurement and broader technology types. It is based on WCAG 2.1 and is part of the European Accessibility Act.

ATAG and UAAG (W3C Guidelines)

ATAG (Authoring Tool Accessibility Guidelines) focuses on the tools used to create content, ensuring that content management systems, for example, allow authors to produce accessible material.

UAAG (User Agent Accessibility Guidelines) focuses on browsers and media players, ensuring they support accessibility features and interact appropriately with assistive tech.

These frameworks may come up in government contracts, accessibility policies, or cross-border digital work. Most organisations in Australia will still default to WCAG 2.1 or 2.2 Level AA, but understanding the broader context is helpful for planning and compliance.

WCAG Compliance Checklist- What Organisations Need to Address

Achieving WCAG compliance involves implementing the proper accessibility features across your website. These features directly support users with diverse needs and align with recognised WCAG success criteria. Each feature is designed to remove barriers or improve the user experience for people with disabilities. 

A well-structured checklist helps organisations assess how accessible their website is.

This section outlines the most important features to review when aiming for WCAG 2.1 or 2.2 Level AA compliance. These items are not exhaustive but represent the minimum scope for any new build or accessibility review.

1. Semantic HTML and Proper Structure

• Use correct heading tags (H1, H2, etc.) in a logical order.
• Avoid skipping heading levels or using styling instead of semantic elements.
• Ensure that lists, tables, and landmarks are coded properly for assistive technology.

2. Keyboard Accessibility

• All interactive elements must be usable without a mouse.
• Test forms, menus, popups, and navigation using only a keyboard.
• Avoid keyboard traps where users can’t move focus or exit components.

3. Alternative Text for Images

• Every image that conveys meaning must have descriptive alt text.
• Decorative images should be marked as such using empty alt attributes. 
• Complex graphics (e.g. charts) should include a text summary.

4. Form Labels and Instructions

• Every input field needs a clear and visible label.
• Placeholder text is not a substitute for a label.
• Provide helpful error messages and mark required fields clearly.

5. Colour Contrast and Visual Clarity

• Ensure text meets minimum contrast ratios (4.5:1 for standard text).
• Avoid using colour as the only way to convey meaning.
• Use accessible design patterns for buttons, links, and alerts.

6. Captions, Transcripts, and Media Controls

• Provide captions for all video content.
• Supply transcripts for audio content.
• Ensure users can pause, stop, or adjust time-based media.

7. Responsive and Accessible Design

• Design must adapt to different screen sizes and orientations.
• Content should not break or overlap when zoomed to 200%.
• Navigation and layout should remain consistent across breakpoints.

8. Clear Language and Readable Content

• Use plain English where possible.
• Avoid jargon or explain it with tooltips or help text.
• Provide meaningful link text (e.g. avoid “click here”).

Need design-specific guidance? Read more about accessible web design.

Accessibility Testing- Automated Tools vs Manual Reviews

Meeting WCAG compliance isn’t just about following a checklist. Testing is where theory meets reality. It’s how you confirm whether your site works for people using assistive technologies or non-standard input methods.

There are two main approaches to accessibility testing: automated tools and manual reviews. Each plays a different role, and neither is complete on its own.

Automated Testing Tools

Automated accessibility tools can scan your website and flag issues quickly. These include:

• WAVE by WebAIM
• axe DevTools
• Lighthouse (built into Chrome)
• Siteimprove Accessibility Checker
• pa11y or Tenon for integration in CI pipelines

These tools detect missing alt text, low contrast, improper heading structures, and form errors. They work well for spotting common technical issues across large volumes of pages.

However, automated tests typically catch only 30–40% of all WCAG compliance problems. They cannot detect issues related to content clarity, logical reading order, or usability of a keyboard workflow.

Manual Testing and User Evaluation

Manual testing fills the gap. This involves navigating your site using only a keyboard, reviewing each page with a screen reader (e.g. NVDA, VoiceOver), and testing everyday user tasks.

High-quality manual reviews also include input from users with lived experience. Feedback from screen reader users or people with cognitive impairments often uncovers barriers that no tool would identify.

Butterfly recommends combining both approaches. Start with automated scans to establish a baseline, then conduct structured manual testing. This layered method provides a realistic view of your site’s performance under real-world conditions.

To book a formal accessibility audit that includes manual testing, book your WCAG compliance audit.

Staying Compliant with WCAG Over Time

Achieving WCAG compliance is a milestone, not an endpoint. Accessibility needs ongoing attention as websites grow, teams change, and standards evolve.

Many organisations meet accessibility requirements during a redesign or tender process, only to see those standards slip over time. New content is added without checks, plugins break compatibility, and user feedback gets overlooked.

Why Compliance Requires Maintenance

• WCAG versions evolve: The shift from 2.1 to 2.2 introduced new success criteria. Future updates will do the same.
• Technology changes: Updates to browsers, devices, and assistive technologies can affect how accessible your site remains.
• Content is dynamic: Even a fully compliant homepage can become non-compliant if embedded video lacks captions or a new form isn’t labelled correctly.
• Teams rotate: New content editors, developers, or designers may not be trained in accessibility practices.

How to Maintain WCAG Compliance Effectively

• Set internal publishing standards aligned with WCAG 2.1 or 2.2.
• Train editors and content creators to use semantic HTML and check contrast, structure, and alt text.
• Run scheduled accessibility tests, especially after updates or major content changes.
• Work with an accessibility partner for periodic audits and guidance on new requirements.

Long-term compliance is easier when accessibility is embedded into everyday workflows, not just managed as a project deliverable. For organisations with reputational, legal, or community responsibilities, maintaining WCAG alignment is part of good governance.

WCAG Guidelines in Australia

In Australia, digital accessibility is supported by both legal obligations and policy expectations. While WCAG itself is a global standard, it plays a central role in local compliance frameworks.

The Disability Discrimination Act 1992 (DDA) makes it unlawful to provide information or services in a way that discriminates against people with disabilities. This includes websites and online services.

The Australian Human Rights Commission has confirmed that failure to make a website accessible may be considered unlawful under the DDA. Although the law does not specify WCAG by name, WCAG 2.0 and 2.1 are used as benchmarks in most Australian government policies, accessibility action plans, and procurement guidelines.

Government and Sector Expectations

Federal and state government departments are expected to meet WCAG 2.1 Level AA for all public-facing websites.

Health, education, and research organisations often follow the same standard due to public accountability and funding requirements.

Local councils and community service providers may also be subject to accessibility commitments through grant obligations or strategic inclusion plans.

Failing to meet WCAG standards can expose organisations to risk, primarily if users or advocacy groups raise complaints.

Read more about website accessibility standards in Australia to understand the legal and regulatory framework in more detail, including the DDA, state-based accessibility policies, and how WCAG aligns with each.

Frequently Asked Questions about WCAG Guidelines and Accessibility Compliance

Need a WCAG Compliance Audit or Expert Advice?

If your organisation is planning a website redesign, responding to a tender, or reviewing its digital risk exposure, now is the right time to check your accessibility compliance.

Butterfly,  an ISO-certified website development agency in Melbourne, offers structured WCAG accessibility audits tailored to the needs of government, healthcare, research, and not-for-profit organisations. Our audits go beyond automated scans. We provide:

• Expert manual testing using assistive technologies
• Evaluation against WCAG 2.1 or 2.2 Level AA
• Clear remediation guidance for your developers or vendors
• A compliance report suitable for governance and procurement use

Our work is conducted in Australia by a local team with deep experience in accessible design, development, and stakeholder engagement.

We understand the specific requirements of mid-sized, for-purpose organisations. We aim to help you meet accessibility standards confidently with the right level of support and technical insight.

Speak to an expert