Web Accessibility: Complete Guide with Tips, Best Practices & Checklist

Web accessibility means making sure everyone can use your websites, including people who rely on screen readers, keyboard input, or other assistive technology. The Web Content Accessibility Guidelines (WCAG), published by the World Wide Web Consortium (W3C), are the global technical standard for achieving this. WCAG 2.2 AA is the current best-practice target, and accessibility laws including the Americans with Disabilities Act (ADA), Section 508, and the European Accessibility Act (EAA) reference WCAG to define their requirements.

According to the World Health Organization, an estimated 1.3 billion people around the world—roughly 16% of the global population—live with a significant disability. People with disabilities have the same right to use the web that everyone else does, and web accessibility is what makes that possible. Building, and maintaining, accessible websites isn’t just the right thing to do—it’s also a requirement under the ADA, Section 508, the EAA, and similar laws in many other countries.

Whether you’re aiming to provide a more equitable web experience for users, or protect your organization from legal risk, this guide is a good place to start. We’ll cover what web accessibility is, why it matters, the standards and principles that define it, and the practical steps any team can take to make websites work better for everyone.

Key insights

• Web accessibility is the practice of ensuring your website works for people with disabilities, including those who use screen readers, keyboard navigation, or voice commands.
• An estimated 1.3 billion people globally—roughly 16% of the world’s population—live with a significant disability. Inaccessible websites exclude people with disabilities from services they have a right to access.
• The Web Content Accessibility Guidelines (WCAG) are the global technical standard for web accessibility, built on four principles: perceivable, operable, understandable, and robust (POUR). WCAG 2.2 AA is the current best-practice target for accessibility conformance.
• Meeting web accessibility standards supports compliance with many U.S. and international laws, including the ADA, Section 508, and the EAA.
• Web accessibility benefits everyone, not just people with disabilities. Accessibility best practices also improve the experience for older users, mobile users, and anyone with a temporary impairment.

What is web accessibility?

Web accessibility refers to designing and developing websites and web applications so people with disabilities can use them. That includes people who navigate by keyboard, use a screen reader to convert text to speech, rely on voice commands, view content with high-contrast or magnified displays, or use any other form of assistive tech.

In practice, web accessibility starts with removing the problems that prevent people with disabilities from using web pages and websites effectively. Some are easy to spot: a video with no captions, an image with no alt text, a form that can’t be completed without a mouse. Others are structural, built into the code in ways that make it impossible for assistive technology to interpret what’s on the screen.

Making websites accessible isn’t just a best practice. It’s recognized as a basic human right under the UN Convention on the Rights of Persons with Disabilities, and it’s the law in the U.S., the EU, Canada, and many other countries.

It’s also good business. Accessible websites reach a wider audience, convert more visitors, and rank better in search results. With the right accessibility tools in place, any team can build and maintain accessible experiences.

Disability categories: Understanding access needs

Disability itself doesn’t create barriers on the web. Inaccessible design does. When websites aren’t compatible with the tools people use, or don’t follow the patterns those tools depend on, users get blocked from content and functionality that should be available to them.

Different communities of users rely on different tools and patterns. Understanding what those are is the starting point for building websites that don’t create barriers in the first place.

Visual

Users who are blind or have low vision navigate the web with screen readers, which convert text to audio or braille output. Users with low vision may also use magnification, high-contrast modes, or custom color settings. Websites need to be compatible with these tools, which means providing proper semantic structure, descriptive alt text for images, sufficient contrast, and content that works at high zoom levels.

Hearing

Users who are deaf or hard of hearing access audio content through captions, transcripts, and visual cues that aren’t dependent on sound. Websites with audio or video need to provide accurate captions and, where relevant, text transcripts. Sound shouldn’t be the only way important information is conveyed.

Neurological

Users with neurological conditions, including epilepsy, migraine, and vestibular disorders, can encounter barriers from motion, flashing, or unpredictable behavior on a page. Websites that respect motion-reduction preferences, avoid flashing content, and maintain predictable navigation are easier and safer to use.

Cognitive

Users with cognitive and learning disabilities rely on websites that communicate clearly and consistently. Plain language, predictable layouts, clear instructions, and well-structured content all reduce the cognitive load required to use a site, which ultimately benefits everyone.

Motor

Users with motor disabilities may not be able to use a mouse, and instead navigate with the keyboard, switch devices, voice commands, or eye-tracking software. Websites need to support these input methods, which means full keyboard operability, visible focus indicators, adequately sized interactive elements, and predictable focus order.

WCAG accessibility guidelines: The universal standard

The World Wide Web Consortium (W3C) published the first Web Content Accessibility Guidelines (WCAG) in 1999, with WCAG 2.0 following in 2008. WCAG establishes universal web accessibility guidelines for websites, web applications, and digital content—covering text, images, audio, video, and the code that structures web pages. It’s also recognized as an international standard, published as ISO/IEC 40500.

WCAG versions

WCAG has undergone several updates over the years:

• WCAG 2.0 (2008): Set the initial accessibility benchmarks. Recognized as an ISO standard.
• WCAG 2.1 (2018): Added 17 new success criteria focused on accessibility for mobile devices, cognitive disabilities, and low vision users.
• WCAG 2.2 (2023): The current version of WCAG, published as a W3C Recommendation on October 5, 2023. Nine new success criteria address mobile usability, cognitive accessibility, and focus management—including touch target sizes and accessible authentication.

WCAG conformance levels

WCAG has three conformance levels. Most organizations target Level AA, the benchmark for compliance with the ADA and many international accessibility laws.

• Level A: The minimum baseline. Websites that don’t meet this conformance level are considered inaccessible to many users.
• Level AA: Removes the most common accessibility barriers. Required by Title II of the ADA (WCAG 2.1) and Section 508 (WCAG 2.0).
• Level AAA: The highest conformance level. Not required for general compliance, and not achievable for all content types.

ARIA, ATAG, and the broader W3C accessibility framework

WCAG covers content and web applications, but the W3C has also published companion standards that help fill in the rest of the picture.

Accessible Rich Internet Applications (ARIA) makes dynamic web applications accessible to adaptive software. It lets developers communicate semantic information about components that standard HTML can’t describe on its own—things like custom dropdowns, modals, or live-updating widgets.

The Authoring Tool Accessibility Guidelines (ATAG) cover the tools used to create web content. The goal is twofold: make the authoring tools themselves usable by people with disabilities, and help content authors use these tools to produce accessible information by default.

Together, WCAG, ARIA, and ATAG form the backbone of accessible web design.

The four principles of web accessibility: POUR and success criteria

The four WCAG principles are summed up in the acronym POUR: perceivable, operable, understandable, and robust. Each represents a different angle on what accessible design means in practice.

Perceivable

Content needs to be detectable through at least one of a user’s senses. Images need a text alternative (alt text). Video and audio need captions and a text transcript. Color alone can’t convey meaning. Semantic HTML matters too, since it structures web pages so screen readers can navigate content logically.

Operable

Users need to be able to interact with a website regardless of how they input. A site should work with a mouse, keyboard, touch, or voice. Keyboard focus needs to be visible, focus should move in a logical order, and interactive elements need to be large enough for users with limited dexterity to activate.

Understandable

Content and interfaces must be clear and predictable. Does every form field and button have an accessible name? Are error messages specific enough that someone with dyslexia or a visual disability can understand what went wrong? Understandable means understandable to everyone.

Robust

Content needs to work across all browsers, devices, and assistive technologies, whether someone is using a screen reader, voice command software, or a braille display. This is where ARIA matters most. It lets developers communicate the role and behavior of custom components that standard HTML alone can’t describe.

Legal implications of inaccessibility

Web accessibility is a legal obligation, and the courts have been clear about it. Lawsuits filed against websites in the United States continue to climb. According to Seyfarth Shaw, 3,117 federal cases were filed in 2025 alone, a 27% jump over the prior year. Total digital accessibility filings topped 5,000 when state court cases are included. Even a single-plaintiff claim typically costs tens of thousands of dollars to settle.

Here are a few key laws to know by region:

United States

In the United States, Title III of the Americans with Disabilities Act (ADA) requires that public accommodations—including businesses that serve the public—are accessible to people with disabilities. The U.S. Department of Justice (DOJ) has clarified, and courts have widely agreed, that the definition of “public accommodations” includes businesses’ websites.

WCAG 2.1 AA is the technical standard that most courts use as a compliance benchmark in ADA Title III cases. Additionally, federal websites must meet WCAG 2.0 AA under Section 508, and a 2024 DOJ rule under ADA Title II requires WCAG 2.1 AA conformance for state and local government entities.

European Union

The European Accessibility Act (EAA) became enforceable on June 28, 2025. It applies to any business with 10 or more employees or €2 million or more in annual turnover that sells to EU consumers, and it covers e-commerce platforms, banking apps, transport services, and most consumer-facing digital products. The presumptive technical standard is EN 301 549, which references WCAG 2.1 Level AA.

Canada

The Accessibility for Ontarians with Disabilities Act (AODA) applies to organizations operating in Ontario. The federal Accessible Canada Act extends obligations across sectors including banking, broadcasting, and telecommunications. Both frameworks reference WCAG as the technical standard.

United Kingdom

The Equality Act 2010 creates a legal duty to make reasonable adjustments for people with disabilities, which courts have consistently interpreted to include digital products and services. The Public Sector Bodies Accessibility Regulations 2018 require all U.K. public sector websites to conform with WCAG 2.1 Level AA and publish an accessibility statement.

Web accessibility checklist: Best practices, tools, and evaluation

A handful of common errors account for most of the accessibility issues on the web. Here are the areas to focus on.

Alt text and link text

Screen readers use alt text (also called a text alternative or alternative text) to describe images out loud. Descriptive alt text helps users with visual disabilities and improves search engine indexing. Every link should clearly describe where it leads, not just say “click here.”

Keyboard and assistive tech navigation

Keyboard access is essential for people who can’t use a mouse. Voice recognition software allows hands-free control, and other tools such as switch access and eye-tracking software give users a range of input options. These tools need to work smoothly with your websites. Making sure your site works with all of these communications technologies matters more than most website owners realize.

Captions and transcripts

Provide captions for all video content. Captioning makes video accessible to users who are deaf or hard of hearing, and it also helps people with attention or processing differences and anyone watching in a noisy environment. A text transcript extends accessibility further and improves searchability.

Color contrast and zoom

Poor color contrast is one of the most common accessibility issues on the web, and failing AA criteria for contrast is one of the issues website owners encounter most often. Make sure your websites deliver enough contrast to meet WCAG AA criteria. The guidelines also indicate that websites should support 200% zoom across mobile devices, which is essential for mobile accessibility.

Forms

Form fields need clear, persistent labels. Enable autofill where possible, make buttons easy to identify, and write specific error messages that tell users how to recover. The understandable principle in WCAG provides specific guidance on form labels and error handling.

Automated and manual accessibility evaluation

How do you know whether your website is accessible? There are two main approaches to evaluating web accessibility: automated testing and manual audits.

The annual WebAIM Million report consistently finds that the vast majority of accessibility errors on the web are common WCAG failures, the kind that automated evaluation tools can catch. However, automated tools only get you so far. Screen reader usability, logical keyboard paths, and accessibility for users with cognitive disabilities all require human review.

The best approach blends automated tools with expert manual review against the current version of WCAG, and a formal accessibility audit is often the best way to get a complete picture.

Web accessibility helps everyone

Designing for accessibility doesn’t just help people with disabilities. Captions make videos easier to follow in noisy environments. Clear keyboard navigation helps power users move through interfaces faster. High-contrast text is easier to read on a phone screen in bright sunlight. Predictable layouts and clear language help anyone who’s tired, distracted, or unfamiliar with a topic.

Design for accessibility, and you design for everyone. And following the guidelines does more than just satisfy compliance requirements; it extends the web to every user who reaches it.

Frequently asked questions

What is meant by web accessibility?

Web accessibility means making sure everyone can use the web, including people with disabilities. It’s about social inclusion and equal access, ensuring that everyone can access information and services online, regardless of how they interact with their device.

What are the four principles of web accessibility?

The four WCAG principles are summed up in the acronym POUR: perceivable, operable, understandable, and robust. Each principle covers a set of WCAG success criteria that websites need to meet to be considered accessible.

What’s the difference between the ADA and WCAG?

The ADA is a law; WCAG is the technical standard organizations follow to meet it. Title III of the ADA has been broadly interpreted to require web accessibility but doesn’t specify exactly how—so courts typically use WCAG 2.1 Level AA as the benchmark for what accessibility means in practice. WCAG 2.1 AA is also the official standard for compliance with the DOJ’s ADA Title II rule on web and mobile accessibility for state and local governments.

How do I make my website accessible?

Start with a clear standard to measure against. WCAG 2.2 AA is the current best-practice target, with each success criteria offering a testable benchmark you can work toward. From there, audit your current state, remediate issues (e.g., alt text, color contrast, keyboard input, form labels) in order of priority, and build accessibility into your ongoing design and development process so new issues don’t pile up.

Combining automated evaluation tools with expert manual review tends to deliver the best results, since automation alone can’t catch everything.

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