What is web accessibility? A plain-English guide

Picture a customer landing on your website, ready to buy. They’re visually impaired and navigating with a screen reader, software that translates your page into spoken audio. But your product images have no descriptions, your buttons aren’t labelled, and the checkout form announces nothing when they tab into it. They leave. You never knew they were there.

That’s what poor web accessibility looks like in practice. It isn’t an edge case, and it isn’t just a legal obligation. It’s a real experience that a significant portion of your visitors may be having right now.

This guide explains what web accessibility is, who it affects, the standards behind it, and how to find out where your website stands.

The short answer

Web accessibility means designing and building your website so that people with disabilities can use it. That includes people who are blind or visually impaired, deaf or hard of hearing, unable to use a mouse, or who process information differently because of a cognitive or learning disability.

The goal is straightforward: anyone who visits your site should be able to read your content, navigate your pages, complete your forms, and do whatever else your site is built for, regardless of how they access the internet.

Web accessibility isn’t a feature you bolt on after the fact. It’s built into how a site is structured, coded, and written.

Who needs web accessibility to work?

Does web accessibility only matter for blind users? No. The World Health Organization estimates that around 16% of the global population lives with some form of disability, and the types of impairments that affect how people use the web vary considerably.

People with visual disabilities

Users who are blind or have severe low vision often rely on screen readers, software that reads page content aloud and converts visual elements into audio or Braille output. For a screen reader to work, images need descriptive alt text, every button and link needs a meaningful label, and the page must follow a logical reading order.

Users with less severe vision impairment may use browser zoom, increase font sizes, or switch to high-contrast display modes. Colour contrast between text and background becomes critical here. Text that looks fine on a standard monitor can become illegible when contrast is too low.

People with hearing disabilities

Users who are deaf or hard of hearing can’t access information delivered through audio or video without alternatives. Any video with spoken content needs accurate captions. Audio-only content needs a written transcript. This is one of the more overlooked areas of accessibility, particularly on sites that rely on explainer videos or recorded demos.

People with motor disabilities

Some users can’t use a mouse. They navigate entirely with a keyboard, pressing Tab to move between interactive elements, Enter or Space to activate buttons and links. If your site requires hovering over a menu to expand it, or relies on drag-and-drop functionality, keyboard-only users may be completely blocked from reaching key pages or completing actions.

Accessible sites ensure that every function, every link, every form field can be reached and operated without a pointing device.

People with cognitive disabilities

Cognitive and learning disabilities cover a broad range: dyslexia, ADHD, memory difficulties, processing speed differences. These users tend to benefit from clear and consistent page layouts, plain language that avoids unnecessary jargon, error messages that explain what went wrong rather than just flashing red, and pages without auto-playing video or animations competing for attention.

Many of these improvements benefit all users. A form that clearly explains what each field expects, with helpful error messages when something goes wrong, is better for everyone, not just those with diagnosed conditions.

Why web accessibility matters for your business

It’s the law in many countries

In the US, the Americans with Disabilities Act applies to websites. Courts have consistently ruled that websites are places of public accommodation, and businesses that fail to make their sites accessible can face lawsuits and settlements. For a closer look at what applies to your situation, see ADA requirements for websites.

In Europe, the European Accessibility Act came into force in June 2025. It requires businesses selling to EU consumers to meet accessibility standards across digital products and services, with the scope expanding over time.

The legal risk is real. But fixating on it misses the bigger picture.

It improves your SEO

Search engine crawlers and screen readers have a lot in common. Both parse the underlying HTML of a page rather than the visual design. An image without alt text is invisible to a screen reader user and to a Google crawler. A page with a clear, logical heading structure is easier for both to navigate.

How accessibility affects your search rankings goes deeper on this, but the headline is simple: addressing common accessibility issues tends to improve your technical SEO at the same time. The two goals reinforce each other.

It makes your site better for everyone

Closed captions were invented for deaf viewers. Today they’re widely used by people watching video in noisy environments, or in places where audio isn’t an option. Keyboard navigation was built for users who can’t use a mouse. It’s also the preference of many power users who find it faster than clicking.

Clear language, consistent navigation, descriptive link text and proper heading structure aren’t trade-offs that make a site harder to use for non-disabled visitors. They improve the experience across the board.

Web accessibility standards: what is WCAG?

What standard does web accessibility follow?

The internationally recognised standard is WCAG, the Web Content Accessibility Guidelines, published and maintained by the World Wide Web Consortium (W3C). WCAG defines specific, testable criteria that websites should meet to be considered accessible.

The guidelines are organised around four principles, often abbreviated as POUR:

• Perceivable — information and interface components must be presentable in ways users can perceive, not just visually
• Operable — interface components and navigation must be operable, not just with a mouse
• Understandable — information and the operation of the interface must be understandable
• Robust — content must work reliably across a wide variety of assistive technologies

Within those principles, WCAG assigns three conformance levels:

• Level A — the minimum. Failing Level A typically means there are serious barriers that block access entirely for some users.
• Level AA — the practical standard. This is what most laws and regulations reference when they require accessible websites.
• Level AAA — the highest level. Full AAA compliance isn’t realistic for most general-purpose websites, but individual criteria at this level are still worth applying where possible.

WCAG 2.1 AA is currently the most widely cited version in legal and regulatory contexts. WCAG 2.2 added further criteria in 2023, with particular attention to mobile usability and cognitive accessibility. For most businesses, WCAG 2.1 AA is the right baseline to work toward. The WCAG guidelines page covers this in more detail.

The most common accessibility issues

Knowing the standard is useful. Knowing what tends to actually go wrong on real websites is more actionable. These are the issues that appear most frequently:

• Missing alt text — images without text descriptions that screen readers can relay to visually impaired users; one of the most common failures on the web, and one of the easiest to address
• Poor colour contrast — text that doesn’t have sufficient contrast against its background, making it difficult or impossible to read for users with low vision or colour blindness
• Unlabelled form fields — input fields with no associated label element, making forms unusable for screen reader users who can’t see placeholder text
• No keyboard access — menus, modals, or interactive components that can’t be reached or activated without a mouse
• Missing skip navigation — without a “skip to main content” link, keyboard users are forced to tab through every navigation item on every page load
• Broken heading structure — headings used for visual styling rather than semantic structure, which breaks the logical reading order that screen readers depend on
• Auto-playing media — video or audio that starts without user interaction, which can be disorienting or distressing for users with cognitive disabilities or vestibular disorders

None of these require rebuilding your site. Most are targeted, specific changes once you know where they are.

How to check if your website is accessible

The fastest starting point is an automated scan. Automated tools test your page against a set of accessibility criteria and report what’s failing, with enough detail to act on.

Scanluma checks your website for accessibility issues against 50+ criteria and returns a detailed report, including the specific HTML that needs attention and plain-language descriptions of each problem. It’s worth being clear about what automated scanning can and can’t do: it identifies a meaningful share of accessibility failures, but a complete audit also involves manual testing and testing with real assistive technologies. A scan is the right place to start, not the final word.

Run a scan, review the report, and you’ll have a clear picture of where your site stands and what to prioritise first.

Next steps

Web accessibility comes down to one question: can everyone who visits your site actually use it? The standards (WCAG), the legal frameworks (ADA, EAA), and the technical specifics are all built around that idea.

The clearest first move is to find out where you stand. A free scan takes seconds and produces a real list of issues, with descriptions plain enough for a business owner to understand and code snippets a developer can act on directly. Start there, and you’ll know exactly what you’re working with.

Run a free accessibility scan on your website