What is WCAG? A plain guide for store owners

WCAG stands for Web Content Accessibility Guidelines. People say it as one word (wuh-cag) or spell out the letters. “Web content” means everything on a page: text, images, buttons, forms, videos and the code that holds them together.

“Accessibility” means people with disabilities can use the site. That includes shoppers who are blind and use a screen reader (software that reads the page aloud), shoppers with low vision who zoom to 200%, people who cannot use a mouse and move through the page with a keyboard, people who are Deaf and need captions, and people with memory or attention difficulties who need clear, predictable pages.

The W3C describes WCAG as covering visual, auditory, physical, speech, cognitive, language, learning and neurological disabilities. It also says plainly that even the strictest level does not meet every person's needs. WCAG is a floor, not a finish line.

The W3C (World Wide Web Consortium) is the group that sets web standards such as HTML and CSS. Its Web Accessibility Initiative (WAI) writes WCAG with input from companies, governments, disability organizations and members of the public. Drafts are published for public comment before they become a final W3C Recommendation.

W3C keeps each published version stable and only corrects errors in later editions. That is why laws can point to a specific version, such as “WCAG 2.0 Level AA”, and know what they are asking for. WCAG 2.2 is also an international ISO standard, ISO/IEC 40500:2025, which the W3C announced on October 21, 2025.

Nobody owns WCAG in a commercial sense. No company, app or widget can issue an official WCAG certificate, and the W3C does not test or approve websites.

WCAG has layers. Each one gets more specific:

The numbers tell you where a rule sits. Take 1.4.3 Contrast (Minimum): principle 1 (perceivable), guideline 4 (distinguishable), success criterion 3. When someone says “you fail 1.4.3”, they mean some text on your page does not stand out enough from its background.

Success criteria are written to be testable, but not tied to any one technology. They say what the result must be, not how to build it. W3C publishes a free “Understanding” page for each criterion that explains the intent, with examples.

Every success criterion sits under one of four principles, often shortened to POUR. Each principle has guidelines under it, 13 in all. Here is how they line up, with a product page example for each:

The guideline tells you where to look in WCAG when a report names a criterion. A failure numbered 2.4 something is about finding your way around the page. One numbered 3.3 is about forms.

Each 2.x version adds rules to the one before it. W3C says content that conforms to WCAG 2.2 also conforms to 2.1 and 2.0. The one rule 2.2 dropped, 4.1.1 Parsing, is now marked in 2.0 and 2.1 as always met for HTML, so it does not break that chain.

WCAG 2.1 added 17 criteria, mostly for phones, low vision and cognitive disabilities. Reflow (pages work at 320 pixels wide) and Non-text Contrast (borders and icons stand out) came in then. WCAG 2.2 added nine more, such as Target Size (Minimum), which asks for tap targets of at least 24 by 24 pixels. Our WCAG 2.2 AA guide lists the new criteria with Shopify examples.

WCAG 3.0 will work differently, with a new structure and scoring. The W3C's page on it, updated September 25, 2026, says it is “not expected to be a completed W3C standard for a few more years” and that WCAG 2 “will not be deprecated for several years after WCAG 3 is finalized.” You do not need to plan for it yet.

Each success criterion has one of three levels. They stack:

• Level A is the minimum. Without it, some shoppers cannot use the page at all. Example: every product photo has alt text.
• Level AA means all A and all AA criteria. It is the level laws use. Example: normal text has a contrast ratio of at least 4.5:1.
• Level AAA adds the strictest criteria, such as 7:1 contrast and sign language for videos. W3C does not recommend requiring it for whole sites, because some content cannot meet it.

For store examples at each level, and what “WCAG 2.1 AA” covers, read WCAG A vs AA vs AAA: which level you need.

“WCAG compliance” is the everyday phrase. WCAG itself uses the word conformance, and it is precise about what that means:

• It is per page. A page conforms at Level AA only if the whole page meets every A and AA criterion, including the version shoppers see on a phone.
• It covers whole processes. WCAG uses an online store as its own example: every page from choosing a product to the end of checkout has to conform, or none of the process does.
• Claims are optional. W3C says you do not need to make a conformance claim to conform. If you do make one, you must name the version, the level and the pages it covers.
• Nobody certifies it. There is no official WCAG badge or certificate. A seal from a vendor is that vendor's opinion.

In practice, stores test their pages, fix what fails, and keep a dated record. That record, and an honest accessibility statement, show the work you have done. Be careful with any tool that promises compliance. In 2025 the US Federal Trade Commission ordered accessiBe to pay $1 million over claims that its widget could make any website compliant.

Most laws name an older version, and all of them stop at Level AA. W3C says content that conforms to WCAG 2.2 also conforms to 2.0 and 2.1, so one target, WCAG 2.2 AA, covers them all.

Each law has its own scope, deadlines and penalties. Read the details for ADA website compliance, AODA website rules in Ontario, other Canadian accessibility laws and the European Accessibility Act.

Shopify runs the platform and the checkout. Shopify publishes accessibility conformance reports for its own products, and its checkout report (March 2026) was tested against WCAG 2.2 A and AA. Everything else shoppers see is yours: the theme, the apps you add, your photos, your videos and your words.

Here is who usually controls what, and where WCAG problems tend to show up:

One quick, real example. WCAG 3.1.1 Language of Page (Level A) asks that the page language is set in the code, so screen readers use the right voice. Shopify's free Dawn theme does this in layout/theme.liquid with a line like the one below. If your theme was customized years ago, open the code editor (Online Store, Themes, then the three-dot menu next to your theme, Edit code) and check that the lang attribute is still there.

<html class="js" lang="{{ request.locale.iso_code }}">

• Thinking a widget makes you meet WCAG. A toolbar on top of the page does not fix the code underneath. In EcomBack's 2025 report, 24.9% of website lawsuits targeted sites that already had an accessibility widget. See why we do not build an overlay.
• Trusting a single score. Automated scans find only part of the problems. Deque's 2021 study of its own audits found automated tests caught about 57% of issues by volume. Keyboard and screen reader checks by a person cover the rest.
• Testing only the home page. Conformance is per page and per process. Test a product page, a collection, the cart and your contact form too.
• Aiming for AAA everywhere. It sounds safer, but W3C itself says some content cannot meet AAA. Get AA right first.
• Waiting for WCAG 3. It is years away, and WCAG 2 stays in force long after it is done.

1. Run the free accessibility checker on your home page, a best-selling product page and a collection page. It flags the problems software can find and names the WCAG criterion for each one.
2. Check your theme colours with the contrast checker. Sale badges, grey text and text over photos fail most often.
3. Put your mouse away. Press Tab from the top of a product page through to checkout. You should always see where you are, and every button, picker and menu should work with Enter, Space and the arrow keys.
4. Listen to one product page with a screen reader. VoiceOver is built into Mac and iPhone, and NVDA is free for Windows.
5. Write down what you found, what you fixed and the date. Our ADA website checklist gives you a list to work through.