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What Is Web Accessibility? The Plain-Language Answer

A website is accessible when someone who cannot see it, cannot use a mouse, or cannot hear it can still do what they came to do. Everything else is detail.

Last reviewed August 28, 2026

Web accessibility means your website works for people with disabilities. Not a stripped-down version of it. The same site, doing the same job. Used differently from the way you use it.

That is the whole idea. The standards, the laws, the audits, the fix guides all exist to answer one question in detail. Can this person finish what they came here for?

Who We are Talking About

It helps to picture actual people rather than a category, because each group hits a different kind of wall on the same page.

  • People who are blind browse by ear, using a screen reader that reads the page aloud. They need every image named, every button labelled, and a page structure that makes sense out loud.
  • People with low vision enlarge everything, often to 400%. They need your layout to reflow instead of clipping text or forcing sideways scrolling.
  • People who are colour blind, roughly one man in twelve, need information carried by something other than colour alone. A red field with no error text says nothing to them.
  • People who cannot use a mouse, through tremor, paralysis, injury, or preference, drive everything by keyboard or voice. Every control has to be reachable and escapable.
  • People who are deaf or hard of hearing need captions on video and transcripts for audio.
  • People with cognitive or learning disabilities need plain language, predictable layouts, clear error messages, and no surprise time limits.

Add temporary and situational cases and the group grows again: a broken wrist, an eye infection, bright sunlight on a phone screen, a noisy train with no headphones. Accessible design is what holds up in all of them.

What the Standard Asks For

The standard is WCAG, the Web Content Accessibility Guidelines, published by the W3C. The current version is WCAG 2.2. Nearly every accessibility law in the world points at it rather than writing its own rules.

WCAG is organised under four principles, known by the initials POUR. Content must be:

  • Perceivable. People can take the information in, by sight, sound, or touch. Alt text, captions, contrast.
  • Operable. People can drive the interface. Keyboard access, no traps, enough time, no seizure risks.
  • Understandable. People can follow it. Readable language, predictable behaviour, helpful errors.
  • Robust. It keeps working with the assistive technology people actually use. Valid markup, correct names and roles.

Underneath sit success criteria, graded A, AA, and AAA. Level AA is the target that laws and contracts name, and at WCAG 2.2 that is 55 rules across A and AA combined. Our learn section explains each one in plain language.

Is It Legally Required?

In most places you do business, yes, though the route differs.

In the US, the ADA does not mention websites, and courts have applied it to them anyway for years. The Department of Justice published a Title II rule setting WCAG 2.1 AA for state and local government. Two deadlines follow from it. April 26, 2027 for entities whose population is 50,000 or more, and April 26, 2028 for everyone smaller and for special district governments whatever their population. Section 508 binds federal agencies and the US Postal Service, and it reaches suppliers through the contracts those agencies write.

In Europe, the European Accessibility Act applies to a broad range of private-sector products and services and has applied since 28 June 2025. Individual countries add their own: France's RGAA, Germany's BFSG, Italy's Stanca Act.

Our laws section covers 38 of them with the deadlines, who's in scope, and what each one names as its standard.

Four Questions That Tell You Where You Stand

You can answer these in ten minutes on your own site, without any tools:

  1. Put the mouse away and press Tab. Can you reach every control, see where you are, and get out of anything you open?
  2. Zoom to 400%. Can you read everything without scrolling sideways, or do you get a horizontal scrollbar and clipped text? Reflow does not have to end up as one column. It has to stop you scrolling in two directions at once.
  3. Turn images off. Does the page still make sense, or do you see filenames where descriptions should be?
  4. Close your eyes and turn on VoiceOver or NVDA. Can you complete one task, start to finish?

If any of those stopped you, they stop your customers. Every day. Our full self-test walkthrough covers all four in detail, and the free 10-page scan handles the mechanical checks for you.

One honest limit

Nobody can make a website permanently accessible, ours included. Sites change every week, and every change can introduce a barrier. What you can do is know where you stand, fix what is broken, and check again after big changes. Any vendor promising permanent compliance from a single purchase is selling you something that does not exist.

Common questions

What is web accessibility in simple terms?
Making your website usable by people with disabilities: those who are blind, have low vision, are colour blind, cannot use a mouse, are deaf, or have cognitive disabilities. The same site doing the same job, used differently.
What is the difference between web accessibility and digital accessibility?
Web accessibility covers websites and web applications. Digital accessibility is the wider term, taking in mobile apps, PDFs and other documents, kiosks, email, and internal software. Websites are the biggest part of most organisations' digital accessibility work.
What does WCAG stand for?
Web Content Accessibility Guidelines, published by the W3C. The current version is WCAG 2.2, and Level AA is the conformance level that laws and contracts name.
Is web accessibility a legal requirement?
In most markets, yes. US courts apply the ADA to websites. The DOJ's Title II rule sets WCAG 2.1 AA for state and local government, with deadlines in April 2027 and April 2028. In Europe, the European Accessibility Act has covered many private-sector services since 28 June 2025.
How many people does web accessibility affect?
The World Health Organization estimates that 1.3 billion people, about 16% of the world, live with a significant disability. Add temporary injuries and situational limits, and the share of your visitors affected on any given day is larger still.

Sources

Keep reading

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Reading about it is the cheap part.

Find out where your site actually stands. The free scan checks 10 pages in a real browser against all 90 supported automated rules, keeps its 27 best-practice checks separate from WCAG findings, and names the rule behind every finding. The full audit adds an expert review and a real blind screen-reader user. From $499, with the report in 5 business days on Rapid and 10 on Standard, and the clock starting at cleared payment.

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