What Is Web Accessibility – Ultimate Guide

The web is meant to be for everyone. Yet, for millions of people with disabilities, many websites remain difficult, or even impossible, to use. Web accessibility is about breaking down those barriers so that every person, regardless of ability, can fully participate online.

In this guide, we’ll explore what web accessibility means, why it matters, the principles that shape it, and how you can test and maintain it. Whether you design, develop, write, or manage content, this guide will help you create a more inclusive web.

What Is Web Accessibility?

Web accessibility is about making websites and web tools usable by everyone, regardless of their abilities or circumstances. In other words, it means designing and developing websites and web tools so that people with disabilities can access and use them.

As the World Wide Web Consortium (W3C) explains (opens in a new tab), web accessibility addresses a wide range of disabilities that affect access to the web. These disabilities or limitations generally fall into three categories, as shown below:

Disability	Examples
Permanent	Blindness, deafness, limited mobility, cognitive impairments such as dyslexia or ADHD
Temporary	Recovering from eye surgery, ear infection, broken arm, post-concussion effects
Situational	Glare from bright sunlight, noisy environment, holding a baby while browsing, multitasking or distractions

By designing with these disabilities and limitations in mind, you reflect the core purpose of web accessibility – ensuring that the web works for everyone.

Why Web Accessibility Matters

Accessibility matters because the web should work for everyone. It should not exclude anyone based on ability, device, or situation. When we design with accessibility in mind, we create equal access to information, services, and opportunities.

Besides equality, there are other important reasons why accessibility matters:

	Why It Matters	Impact
Legal	Many countries have accessibility laws	You could face lawsuits under ADA, EAA, or other local laws.
Business	Accessibility broadens your audience	More users can engage, convert, and stay loyal, including people with disabilities.
SEO	Accessible sites perform better in search	Features like alt text, proper heading structure and clean HTML support search rankings.
Usability	It improves the experience for everyone	Clear labels, good contrast, and captions help all users, not just people with disabilities.

The web is fundamentally designed to work for all people, whatever their hardware, software, language, location, or ability. It’s important to protect that vision so the web remains open and usable for everyone. When this goal is met, the web becomes truly inclusive.

What Are the 4 Principles of Web Accessibility?

The 4 principles of web accessibility are summed up as POUR: Perceivable, Operable, Understandable, and Robust. They ensure everyone, including people with disabilities, can perceive, understand, navigate, and interact with the web.

	What It Means	Example
Perceivable	Users must be able to recognise and process content using at least one sense (sight, hearing, touch)	For people who are blind or rely on screen readers, visual elements like images or videos can be a challenge. To make content perceivable for them, always provide text alternatives for non-text content, such as images or videos.
Operable	Users must be able to navigate and interact with the interface	For someone who can’t use a mouse, every part of your site should still be operable with a keyboard or other assistive devices. A user should be able to move through links, buttons, and forms using keys like Tab, Enter, or Space, or with input methods provided by their assistive technology, without getting stuck.
Understandable	Content and interface must be clear and predictable so users can comprehend and use them	For someone with a cognitive disability, vague error messages or inconsistent layouts can make a site confusing and hard to use. Clear instructions, predictable navigation, and error messages that explain exactly what to fix help them complete tasks with confidence.
Robust	Content must be compatible with current and future tools, including assistive technologies	For someone who relies on a screen reader, poorly coded buttons or links may not be announced correctly, making the site unusable. By using valid HTML and proper ARIA roles, you ensure that assistive technologies can interpret and present content accurately, both now and as technology evolves.

What Are the Web Accessibility Standards?

The primary standard for web accessibility is the Web Content Accessibility Guidelines (WCAG), developed by the W3C. WCAG explains how to make websites and digital content more accessible to people with disabilities.

There are different versions of WCAG, each expanding the guidelines to address new technologies and wider accessibility needs:

• WCAG 2.0 (2008) established the core principles and success criteria.
• WCAG 2.1 (2018) added requirements for mobile accessibility, low vision, and cognitive disabilities. It is the widely adopted version today.
• WCAG 2.2 (2023) introduced new success criteria for users with low vision, limited mobility, and cognitive needs.

All WCAG versions include three levels of conformance: Level A fixes the most critical issues that affect many users, Level AA removes additional barriers that impact a wider range of people, and Level AAA provides the highest level of accessibility, covering more specific needs.

Other related guidelines from W3C, such as WAI-ARIA (for dynamic content and interactive elements), ATAG (for authoring tools), and UAAG (for browsers and media players), support accessibility but are less widely adopted than WCAG.

What Are the Web Accessibility Laws?

Many countries enforce accessibility through laws and regulations, making it a legal as well as ethical responsibility. These regulations aim to remove barriers so that people with disabilities can fully participate in the digital world.

Here are some examples of the more prominent laws and guidelines across the globe.

Region / Country	Legislation
United States	Americans with Disabilities Act (ADA) (public and private), Section 508 of the Rehabilitation Act (federal)
European Union	Web Accessibility Directive (public), European Accessibility Act (EAA) (private)
United Kingdom	Equality Act 2010 (public and private), Public Sector Bodies Accessibility Regulations (public)
Canada	Accessible Canada Act (ACA) (federal), Accessibility for Ontarians with Disabilities Act (AODA) (provincial, public and private)
Australia	Disability Discrimination Act (DDA) (public and private)

Most of these laws reference WCAG as the benchmark. Non-compliance can result in lawsuits, fines, or reputational damage, so aligning with both guidelines and legal requirements is critical.

How to Test for Web Accessibility

The World Wide Web Consortium (W3C), the international standards organisation for the web, has developed the Web Content Accessibility Guidelines (WCAG) to provide a framework for achieving web accessibility.

To test for web accessibility, you need to measure your website or web tool against the criteria outlined in the WCAG. These guidelines are structured around the POUR principles of accessibility (opens in a new tab). Web accessibility testing typically involves four steps:

1. Automated testing: Use tools to quickly identify common accessibility issues.
2. Manual testing: Check content and interactions manually for issues that automated tools miss.
3. Assistive technology testing: Ensure usability with screen readers and other assistive tools.
4. User testing: Gather feedback from people with disabilities to identify real-world barriers.

Let’s explore each step in detail.

1. Automated testing

Automated tools provide a quick first pass at identifying accessibility issues, making them a useful starting point. They can flag common problems such as missing alt text, low colour contrast, incorrect heading order, and missing form labels.

You can use WebYes for automated testing. It scans multiple pages in seconds and generates detailed reports that clearly show where fixes are needed. It also provides AI-powered code fix suggestions, which you can review and implement to improve accessibility.

2. Manual testing

Automated tools can’t catch all accessibility issues; they typically identify only a fraction of them. Manual testing helps uncover the rest of the issues that require human judgment, such as ensuring the keyboard focus order is logical and that users can navigate the site without a mouse.

Manual testing can be done by hiring an accessibility expert or working with a professional service for a detailed audit. You can also perform your own checks using guided tools like WebYes, which walk you through the process step by step.

3. Assistive technology testing

Many people with disabilities use assistive technologies to browse the web. Testing with tools like NVDA, JAWS, or VoiceOver (for screen reading), magnifiers, or speech recognition software helps ensure your site is usable for these users.

Using different assistive technologies, check that content is read in a logical order, labels are accurate, and interactive elements are announced correctly. This helps make sure the site works in real life for people who rely on assistive tools.

4. User testing

The most valuable insights often come from real users. Involving people with disabilities in your testing process reveals barriers you might not have noticed. They can highlight navigation challenges, unclear content, or inaccessible interactive elements.

You can find participants through disability advocacy groups, local community organisations, and online accessibility forums. Platforms like Fable, AccessWorks, or User Interviews also connect you with people with disabilities for structured usability testing.

Common Web Accessibility Issues

Some accessibility problems remain widespread across the web, showing up on countless websites. Each year, WebAIM publishes its Million report (opens in a new tab), analysing one million homepages, and the same barriers continue to surface year after year.

Here are the most common web accessibility issues:

Issue	What It Means for Users
Low contrast text	Hard to read for people with low vision or colour blindness
Missing alt text	Screen reader users can’t understand the purpose of images
Unlabeled form fields	Forms are confusing or unusable with assistive technologies
Empty links and buttons	Screen reader users don’t know what the link or button does
Missing language declaration	Screen readers may mispronounce content
Keyboard traps	Users who rely on a keyboard can get stuck and be unable to move through the page
Poor heading structure	Makes it difficult for screen reader users to navigate and understand the page hierarchy
Multimedia without captions	Excludes deaf and hard-of-hearing users from accessing video or audio content
Tables without headers	Screen reader users can’t understand the data relationships in tables

We also ran tests (opens in a new tab) using our WebYes website accessibility testing tool to check websites for EAA compliance ahead of the European Accessibility Act deadline. The findings echoed what WebAIM’s Million report highlights.

How to Create an Accessible Website

Creating an accessible website is about removing barriers so everyone, including people with disabilities, can use it. The Web Content Accessibility Guidelines (WCAG) provide guidelines to help you design and build websites that are usable, inclusive, and accessible to all.

To put these guidelines into practice, consider accessibility at every stage of your website, from planning and design to development and ongoing maintenance. Below are the key steps to help you create an accessible website.

1. Define accessibility goals for your website
2. Design your site with inclusive layouts
3. Build your website with semantic, accessible code
4. Test your site with tools and assistive tech
5. Maintain accessibility as your site evolves

Let’s look at each of these steps in detail.

1. Define accessibility goals for your website

Start by making accessibility a core requirement, not an optional add-on. Set clear goals based on WCAG standards, ideally aiming for Level AA compliance. Document these goals so everyone on your team understands the importance of accessibility from the beginning.

2. Design your site with inclusive layouts

Good design makes a site easier for everyone to use. Choose colour combinations with strong contrast, use readable fonts, and keep layouts flexible for different screen sizes. Ensure navigation is consistent and predictable so users don’t get lost.

3. Build your website with semantic, accessible code

Use semantic HTML tags for headings, lists, and landmarks instead of relying on visual styling. Add alt text for images, descriptive labels for forms, and make sure the site can be fully navigated with a keyboard. Use ARIA roles only when necessary to support assistive technologies.

4. Test your site with tools and assistive tech

Testing is essential to ensure your site works for everyone. Use tools like WebYes for quick checks, then rely on manual testing for more nuanced issues. Finally, test with assistive technologies like screen readers to confirm a smooth, real-world experience.

5. Maintain accessibility as your site evolves

Accessibility isn’t a one-time task. Re-test your site whenever you add new content or features, and make accessibility part of your update workflow. Train your team regularly so that accessibility becomes a shared responsibility across design, development, and content creation.

Keep Web Accessibility at the Heart of Your Work

Web accessibility ensures that everyone, regardless of ability or circumstance, can use and benefit from the web. And its future depends on the choices we make. Every decision in design, development, and content creation shapes whether people are included or left out.

That’s why accessibility should be built into your workflow, not left for later. By shifting it to the left and addressing accessibility from the earliest planning stages through to post-launch updates, you can prevent barriers before they appear.

When accessibility becomes part of how you work, you help create a web that welcomes everyone.

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