Website accessibility basics: what business owners need to know about WCAG

The short answer

WCAG, the Web Content Accessibility Guidelines from the W3C, sets out how to make websites usable by people with disabilities. It is organised around four principles: perceivable, operable, understandable and robust. Most organisations aim for level AA. Start with text contrast, keyboard use, image descriptions, clear forms and headings, then test regularly.

What WCAG is and who writes it

WCAG stands for Web Content Accessibility Guidelines. It is published by the World Wide Web Consortium (W3C), the body that also maintains many other web standards. The guidelines are a set of testable statements, called success criteria, that describe what a page should do so that people with visual, hearing, motor or cognitive disabilities can use it.

The current version is WCAG 2.2, and the W3C publishes it as a Recommendation on its website. Check the W3C site for the latest published version before you write a brief or a contract, because newer versions do appear.

WCAG is not a law. Some laws and public-sector rules refer to it, and those rules differ by country, so ask a qualified lawyer what applies to your business. This guide is general information only.

Why it matters beyond compliance

Accessibility is easy to treat as a box to tick. In practice the same changes help a wide range of people: someone using a screen reader, someone with a broken wrist who navigates with the keyboard, someone reading a phone screen in bright sunlight, someone who simply needs larger text.

It also tends to improve the site for everyone else. Clear headings, descriptive link text and labelled form fields make pages easier to scan and easier for search engines to understand. A business that makes it hard for a person to book, buy or enquire is losing that person, whatever the reason.

The four principles

WCAG groups its criteria under four principles, often remembered as POUR.

• Perceivable: information can be taken in through more than one sense. Images have text alternatives, video has captions, and text is readable against its background.
• Operable: every function works with a keyboard, there is enough time to read and act, and nothing flashes in a way that could harm someone.
• Understandable: the language is clear, navigation is predictable, and forms explain errors in words.
• Robust: the code is clean enough that browsers and assistive technology, such as screen readers, can interpret it reliably.

When a developer says a page "fails" a criterion, it belongs to one of these four groups, which helps you decide who should fix it: a designer, a writer or a developer.

Levels A, AA and AAA

Each success criterion is given a conformance level. Level A covers the most basic requirements. Level AA adds more, and is the level most organisations and policies name as their target. Level AAA is the most demanding, and the W3C itself notes that it is not realistic to meet every AAA criterion on every site.

If a supplier promises "WCAG compliance" without naming a version and a level, ask which they mean.

Seven checks you can make yourself

You do not need special software to find the worst problems. Work through these on your key pages: home, contact, a service or product page, and any form.

1. Tab through the page. Press the Tab key repeatedly. Can you reach every link, button and field? Can you always see where the focus is? Can you leave a menu or pop-up again?
2. Check text contrast. Under WCAG, normal-size text needs a contrast ratio of at least 4.5 to 1 against its background at level AA, and large text at least 3 to 1. Free contrast checker tools will measure your colours.
3. Look at images. Meaningful images need a short text alternative describing what they show or do. Decorative images should have an empty alternative so screen readers skip them.
4. Read the headings. There should be one main heading, then sub-headings in a logical order. They should work as an outline of the page.
5. Make link text meaningful. "Read our returns policy" tells a screen reader user where the link goes. "Click here" does not.
6. Zoom in. Enlarge the text in the browser. Nothing should overlap or disappear, and you should not need to scroll sideways on a phone. See responsive web design explained.
7. Do not rely on colour alone. An error shown only in red is invisible to some people. Add words or an icon.

Forms, video and documents

Forms are where accessibility problems cost you the most, because they stand between a visitor and an enquiry. Every field needs a visible label that is linked to it in the code, not just placeholder text that vanishes when typing starts. Error messages should say what went wrong and how to fix it. Our guide to contact form best practices covers this in more detail, and spam protection without CAPTCHA explains why puzzle tests can shut people out.

Video needs captions, and audio-only content needs a transcript. PDFs should be real text with headings, not scanned pictures of pages. If you embed a third-party widget, such as a booking tool or chat box, test it too, because its problems become your problems.

Who should do what

Accessibility is shared work, and it helps to know who owns which part. Designers choose colours, type size and layout, so they carry contrast and spacing. Writers handle headings, link wording, image descriptions and plain language. Developers handle the code that makes keyboards, forms and screen readers behave. Whoever manages the site checks new content before it goes live.

Ask each person to include one accessibility check in their normal routine, rather than leaving it all to a final audit. A short review of each new page, using the seven checks above, catches most slips while they are still cheap to fix. Keep a simple log of issues found, who fixed them and when, so progress is visible and old problems do not return after a redesign.

If you hire an outside specialist for an audit, ask for a report that explains each problem in plain words, shows where it occurs and suggests a fix, not just a list of criteria numbers.

Building it into your process

Fixing accessibility after launch is slower than building it in. When you brief a developer, name the target, such as "WCAG 2.2 level AA", and ask how they will test. Ask for testing with the keyboard and with at least one screen reader, as well as automatic scanners. Automatic tools find only part of the problems, so human testing is still needed.

Add accessibility to your routine too. Re-check when you redesign, add a new plugin or publish new templates, and see it as part of regular upkeep, like the items in a website maintenance plan. Consider publishing a short accessibility statement that tells visitors how to ask for help if they find a barrier, and respond when they do.

Related guides

• Website development
• Website Contact Forms: Best Practices
• Website Maintenance Plan: What It Should Include
• Website security checklist for small business
• Website accessibility checklist and why it matters
• Website redesign seo checklist

Questions and answers

What is WCAG?

WCAG is the Web Content Accessibility Guidelines, published by the W3C. It lists testable criteria for making web content usable by people with disabilities, grouped under four principles: perceivable, operable, understandable and robust.

Which WCAG level should my business aim for?

Level AA is the usual target for business websites. Level A is the minimum and level AAA is not expected on every page. Ask a qualified lawyer whether any rule in your country names a specific version or level.

Is website accessibility a legal requirement?

It depends on your country, your sector and who you serve. Some laws refer to WCAG. This guide is general information only, so ask a qualified lawyer about the rules that apply to you.

Can an automatic scanner make my site accessible?

No. Scanners are useful for spotting missing text alternatives or low contrast, but they find only part of the issues. Keyboard testing, screen reader checks and a read-through by a person are still needed.

What is the quickest accessibility win?

Try using your own site with only the keyboard. Fixing hidden focus outlines, unreachable menus and unlabelled form fields tends to help a large number of visitors for little effort.

Do I need an accessibility statement?

It is not a substitute for fixing problems, but a short statement that names your target, lists known gaps and gives a contact method is a helpful courtesy. Check current guidance for your region.