# WCAG *Web Content Accessibility Guidelines* WCAG is the W3C standard for making web content usable by people with disabilities. It defines three conformance levels — A, AA and AAA — and AA is the one European law, public tenders and corporate contracts actually ask for. **Canonical:** https://spoko.space/glossary/wcag/ **Language:** en **Category:** Accessibility **Also known as:** WCAG 2.1, WCAG 2.2, web accessibility standard **Published:** 2026-09-22 **Glossary:** https://spoko.space/glossary/ --- ## What it is {#what-it-is} WCAG is a list of testable requirements, not a philosophy. The current version most people mean is 2.1, published in 2018; 2.2 arrived in 2023 and adds nine criteria. Everything is grouped under four principles — content has to be **perceivable, operable, understandable and robust** — and each principle holds success criteria that a page either meets or does not. The levels matter more than the version. Level A is the floor, AA is the working standard, AAA is a target nobody holds a whole site to. WCAG 2.1 at A and AA together is 50 success criteria, and that is the set worth planning around. ## Why it matters if you are paying for a website {#why-it-matters-if-you-are-paying-for-a-website} Because AA is the number that turns up in contracts. The European Accessibility Act points at EN 301 549, and EN 301 549 points at WCAG 2.1 level AA. Public procurement in Poland has referenced it for years, and large companies increasingly push the same clause down to their suppliers. When a tender says "accessible", this is the thing it means. The second reason is cheaper to act on: most of the criteria are also plain build quality. Labelled form fields, a visible focus ring, contrast you can read on a laptop in daylight, a page that survives being zoomed to 200%. None of that is charity work. ## What it looks like on this site {#what-it-looks-like-on-this-site} Every build runs axe over 42 routes in both colour themes. That is the easy half. The harder half is a second checker I wrote, because axe cannot judge some criteria at all and abstains on others: reflow, text spacing, focus visibility, focus not obscured, dialog focus, autocomplete, label-in-name — and contrast, which it reports as *incomplete* rather than failing whenever a gradient or a pseudo-element sits anywhere above the node. Two findings from running it on my own site are worth stating plainly. The brand blue measures 3.9:1 against white: fine for a fill or an icon, under AA for anything set at body size, which is why three separate blues exist in the stylesheet instead of one. And for a while the site knowingly failed criterion 2.4.11: the cookie banner was a floating card pinned over the page, and it could cover a focused element at the bottom of the viewport. That one accepted failure was why the copy here said 2.1 AA and not 2.2. The banner now hangs from a sticky dock inside the page instead — it moves up with the content before the footer and the browser scrolls a focused link clear of it — so the failure is gone and the claim is 2.2 AA. ## What WCAG is not {#what-wcag-is-not} It is not a plugin. The overlay widgets sold as "instant compliance" are, at best, a second interface bolted over the broken one; the accessibility community has spent years documenting why they make things worse, and buying one does not change what an audit finds. It is also not a score. A tool that reports zero violations has told you that it found nothing it knows how to look for — which, on a page whose real problem is a heading order that makes no sense to someone using a screen reader, is not the same as passing. ## Related terms {#related-terms} - [CLS](https://spoko.space/glossary/cls/): CLS scores how much a page jumps around while it loads, on a unitless scale where 0.1 or less is good. Every element that moves without the visitor causing it adds to the score, weighted by how far it moved and how much of the screen it took. — Markdown: https://spoko.space/glossary/cls.md - [Core Web Vitals](https://spoko.space/glossary/core-web-vitals/): Core Web Vitals are the three metrics Google collects from real Chrome visits: LCP for loading, INP for responsiveness and CLS for visual stability. A URL passes when 75% of its visits are inside the good threshold. — Markdown: https://spoko.space/glossary/core-web-vitals.md - [contrast ratio](https://spoko.space/glossary/contrast-ratio/): Contrast ratio is the measured difference in relative luminance between text and its background, from 1:1 to 21:1. WCAG asks for at least 4.5:1 for normal text, 3:1 for large text, and 3:1 for the parts of a control that convey what it is. — Markdown: https://spoko.space/glossary/contrast-ratio.md ## Where I write about this {#related-posts} - [10 Traits of an Effective Website | Conversion Optimization Guide](https://spoko.space/blog/effective-website/) — Markdown: https://spoko.space/blog/effective-website.md An effective website is one that converts visitors into customers. 10 concrete traits that decide the outcome — and how to verify each of them on your own site. - [Modern Website Design 2026 — Trends, Navigation and Inspiration](https://spoko.space/blog/modern-website-design-trends/) — Markdown: https://spoko.space/blog/modern-website-design-trends.md Bento grid, dark mode, kinetic typography, CSS scroll animations and the evolution of the hamburger menu — a practical guide to 2026 web design trends with examples and an inspiration list. ## See also {#see-also} - [Accessibility audit (WCAG 2.2 AA)](https://spoko.space/accessibility/) ## Sources {#sources} - [Web Content Accessibility Guidelines (WCAG) 2.1](https://www.w3.org/TR/WCAG21/) — The standard itself — the success criteria, verbatim. - [Understanding WCAG 2.1](https://www.w3.org/WAI/WCAG21/Understanding/) — W3C notes on the intent of each criterion and how to satisfy it. - [EN 301 549](https://www.etsi.org/deliver/etsi_en/301500_301599/301549/) — The European standard that turns WCAG into a procurement requirement.