The plain-English explainer
What is web accessibility?
Web accessibility means building digital products that everyone can use, including people with disabilities. The shared standard is WCAG, and three legal drivers now make it a duty for most organisations: the European Accessibility Act in the EU, and the ADA and Section 508 in the US. This page explains all of it without the jargon.
Reviewed by the EAA Navigator team
TL;DR
- What: designing and building websites, apps and documents so people with disabilities can use them.
- The standard: WCAG, built on four principles, Perceivable, Operable, Understandable, Robust (POUR). Level AA is the target.
- The laws: the EAA (EU), the ADA and Section 508 (US), with EN 301 549 as the EU harmonised standard.
- Who: most businesses selling to or serving the public, plus public-sector bodies.
- How: audit, fix, publish an accessibility statement, then maintain. Overlays alone do not make you compliant.
Three legal drivers
EAA
The European Accessibility Act. EU law for many products and services, applying from 28 June 2025.
ADA & 508
US law. Courts apply the ADA to websites; Section 508 covers federal procurement.
WCAG AA
The technical standard they all converge on, via EN 301 549 in the EU.
Different laws, one practical target: WCAG 2.1 AA. See the full deadline tracker.
What web accessibility is, and who it is for
Web accessibility is the practice of building websites, apps and digital documents so that people with disabilities can perceive, understand, navigate and interact with them on an equal footing. That includes people who are blind or have low vision, who are deaf or hard of hearing, who have motor disabilities, and who have cognitive or learning disabilities. Many of these users rely on assistive technology, such as screen readers, screen magnifiers, voice control or keyboard-only navigation. W3C / WAI
Accessibility is not a niche concern. The World Health Organization estimates that around 1.3 billion people, about 16 percent of the world, or one in six, experience significant disability. WHO Building for them also tends to build a better site for everyone: clearer structure, better contrast, captions, and pages that work on more devices and connections.
The POUR principles
The whole field rests on four principles, known by the initials POUR. Content has to be:
Perceivable
Users must be able to perceive the information. Think text alternatives for images, captions for video, and enough colour contrast to read the text.
Operable
Users must be able to operate the interface. Everything must work by keyboard, with visible focus, no keyboard traps, and no content that flashes dangerously.
Understandable
Content and operation must be understandable. Use clear language, predictable navigation, and helpful, specific error messages on forms.
Robust
Content must work reliably with current and future tools, including assistive technology. Use valid, well-structured code and correct names, roles and values.
WCAG: the standard everyone uses
The Web Content Accessibility Guidelines (WCAG) turn the four principles into testable success criteria. They are published by the W3C, the body that sets web standards, and they are the international benchmark for digital accessibility. WCAG 2.2
WCAG has three conformance levels:
- Level A covers the most basic requirements.
- Level AA is the practical and legal target. It is what EN 301 549, the DOJ Title II rule, Section 508 and most ADA case law point to.
- Level AAA is the highest bar and is not expected across a whole site.
When people say a site should be accessible, they almost always mean WCAG 2.1 Level AA (with WCAG 2.2 AA as the current best-practice version). For the versions, levels and what changed in 2.2, see our full WCAG explainer.
The three legal drivers
Three separate legal frameworks push organisations towards the same WCAG AA target.
EAA (EU)
The European Accessibility Act, Directive (EU) 2019/882, covers many products and services and applies from 28 June 2025. Directive (EU) 2019/882
ADA & 508 (US)
US courts apply the ADA to websites, the DOJ Title II rule adopts WCAG 2.1 AA, and Section 508 covers federal procurement. DOJ web rule
EN 301 549
The EU harmonised standard. Its Chapter 9 incorporates WCAG 2.1 AA, so meeting WCAG AA gives a presumption of conformity in the EU. EN 301 549 v3.2.1
Who must comply
The short answer is: most organisations that sell to, or serve, the public. Under the EAA, businesses placing covered products on the EU market or providing covered services (e-commerce, banking, transport, e-books and more) must comply, with a narrow exemption for micro-enterprises providing services. European Commission Public-sector bodies are covered by the separate Web Accessibility Directive.
In the US, ADA Title III reaches the websites of businesses open to the public, the DOJ Title II rule binds state and local government, and Section 508 applies to federal agencies and the companies that sell to them. Even where a law does not name you directly, your customers and procurement partners increasingly ask for proof of conformance, often a VPAT.
Why it matters
The need is large and the gap is wide. WebAIM's 2025 analysis of the top one million home pages found that 94.8 percent had detectable WCAG failures, with around 51 errors per home page on average. The most common problems were low-contrast text, missing alternative text on images, and missing form labels. WebAIM Million 2025
Beyond the legal duty, accessibility widens your audience, improves usability for everyone, helps with search engine optimisation, and tends to produce more robust, maintainable code. It is rarely wasted effort.
Overlays and automated tools are not enough
How to get compliant, in four steps
Compliance is a process, not a product you can bolt on. The reliable path has four steps.
1. Audit
Test the site against WCAG 2.2 AA using automated scans plus manual and assistive-technology testing. Automated tools alone miss most issues. The WCAG 2.2 AA checklist walks you through what to check.
2. Fix
Work through the issues in priority order, starting with the ones that block users most. Use the WCAG checklist to track progress, and the guides for specific fixes.
3. Publish a statement
Write an accessibility statement: your compliance status, known issues, a feedback channel and a contact. It is mandatory for public-sector bodies and expected of EAA service providers.
4. Maintain
Accessibility decays as content and features change. Build it into design and development, and retest regularly so new issues do not creep back in.
Where to go next
By the numbers
Web accessibility in a few figures
People, about 16% or one in six worldwide, who experience significant disability (WHO).
Of the top one million home pages had detectable WCAG failures in 2025 (WebAIM).
The WCAG conformance level the EAA, the ADA case law and Section 508 all target.
The share of WCAG issues automated tools can catch. The rest need human testing.
Sources: WHO, WebAIM Million 2025 and the Overlay Fact Sheet.
FAQ
People also ask
- What is web accessibility?
- Web accessibility means designing and building websites, apps and digital documents so that people with disabilities can perceive, understand, navigate and interact with them. That includes people who are blind or have low vision, are deaf or hard of hearing, have motor or cognitive disabilities, or use assistive technology such as screen readers, magnifiers or keyboard-only navigation. The recognised standard is WCAG.
- What is WCAG?
- WCAG stands for the Web Content Accessibility Guidelines, published by the World Wide Web Consortium (W3C). It is the international standard for digital accessibility, organised around four principles (Perceivable, Operable, Understandable, Robust) and three conformance levels (A, AA, AAA). Level AA is the target almost every law points to.
- Which laws require web accessibility?
- In the EU, the European Accessibility Act (Directive (EU) 2019/882) covers many private-sector products and services from 28 June 2025, and the Web Accessibility Directive (2016/2102) covers public-sector sites and apps. In the US, courts apply the ADA to websites, the DOJ Title II rule sets WCAG 2.1 AA for state and local government, and Section 508 covers federal procurement. They converge on WCAG AA.
- What conformance level do I need to meet?
- WCAG 2.1 Level AA is the practical target everywhere. The EU harmonised standard EN 301 549, the DOJ Title II rule and Section 508 all point to WCAG AA, and most ADA settlements use it too. AAA is not expected across a whole site.
- Do accessibility overlays or widgets make my site compliant?
- No. Overlay and widget products (such as accessiBe, AudioEye or UserWay) cannot make a site conformant. Automated tools detect only about 30 to 40 percent of WCAG issues; the rest need human testing. The Overlay Fact Sheet, signed by more than 1,000 accessibility professionals, rejects overlays as a compliance solution, overlay-equipped sites are still sued, and in 2025 the FTC finalised a $1,000,000 order against accessiBe for deceptive claims.
- How do I make my website accessible?
- Audit your site against WCAG 2.2 AA (automated scan plus manual and assistive-technology testing), fix the issues in priority order, publish an accessibility statement, and keep testing as the site changes. Build accessibility into your design and development process so new issues do not creep back in.
- Why does web accessibility matter?
- Around 1.3 billion people, roughly 16 percent of the world or one in six, experience significant disability (WHO). Yet WebAIM found that 94.8 percent of the top one million home pages had detectable WCAG failures in 2025. Beyond the legal duty, accessible sites reach more customers, work better on more devices and tend to be better built overall.
- How long does it take to become compliant?
- It depends on the size of the site and how many issues an audit finds, but accessibility is best treated as an ongoing programme rather than a one-off project. A typical path is an audit in weeks, a remediation phase over the following weeks or months, then continuous testing as content and features change.
This is guidance, not legal advice
Sources
- [1]Web Content Accessibility Guidelines (WCAG) 2.2 (W3C Recommendation)retrieved 9 Jun 2026
- [2]WCAG overview (W3C / Web Accessibility Initiative)retrieved 9 Jun 2026
- [3]Directive (EU) 2019/882 (European Accessibility Act), EUR-Lexretrieved 9 Jun 2026
- [4]European Commission: European Accessibility Actretrieved 9 Jun 2026
- [5]EN 301 549 v3.2.1, the EU harmonised ICT accessibility standard (ETSI)retrieved 9 Jun 2026
- [6]US DOJ: ADA Title II web rule fact sheetretrieved 9 Jun 2026
- [7]US Access Board: Section 508 / ICT standardsretrieved 9 Jun 2026
- [8]WebAIM Million 2025 (annual accessibility analysis)retrieved 9 Jun 2026
- [9]World Health Organization: Disability fact sheetretrieved 9 Jun 2026
- [10]Overlay Fact Sheetretrieved 9 Jun 2026
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