WCAG accessibility basics: what every Canadian website owner should understand

What WCAG is and who writes it

The Web Content Accessibility Guidelines (WCAG) are published by the World Wide Web Consortium (W3C) through a working group called the Web Accessibility Initiative (WAI). The W3C is the international body that maintains the standards the web runs on — the same organization responsible for HTML and CSS standards.

WCAG has been through multiple versions. WCAG 2.0 was published in 2008. WCAG 2.1 in 2018 added criteria specifically addressing mobile devices, low vision, and cognitive disabilities — the three areas most underserved by the earlier version. WCAG 2.2, published in 2023, added further criteria around focus indicators and authentication. When Canadian legislation references WCAG, it typically specifies WCAG 2.0 Level AA as a minimum, though WCAG 2.1 Level AA is now the practical current standard.

The guidelines are organized as testable success criteria — specific, verifiable statements about what a website must do or avoid. This makes them useful for developers and auditors because each criterion can be checked objectively.

The four principles: POUR

All WCAG success criteria sit under four high-level principles, known by the acronym POUR. Understanding these principles helps make sense of why specific requirements exist.

Perceivable means that all information and interface components must be presented in ways that users can perceive — which means not relying solely on a single sense. The most common application: images need text alternatives so screen reader users can understand them; audio needs captions or transcripts so deaf users can access the content; colour alone cannot be the only way of conveying information.

Operable means that users must be able to navigate and use the interface. Crucially, this includes users who cannot use a mouse — keyboard-only users, screen reader users, and people using switch access devices all need to be able to operate every part of your site through the keyboard alone. This also covers things like giving users enough time to complete tasks, not using flashing content that could trigger seizures, and helping users navigate and find content.

Understandable means that the content and operation of the interface must be comprehensible. This includes writing clearly, making pages behave predictably, and helping users avoid and recover from errors — for example, giving a useful error message when someone fills out a form incorrectly rather than just a generic "error" notification.

Robust means content must be robust enough to be reliably interpreted by a wide variety of current and future user agents, including assistive technologies. In practice this means using valid, semantic HTML rather than hacking things together with non-standard markup.

The three conformance levels: A, AA, and AAA

WCAG organizes its success criteria into three levels of conformance: A (minimum), AA (mid-range, the de facto legal standard), and AAA (highest, which WCAG itself acknowledges is not achievable for all content).

Level A covers the most fundamental requirements — things that, if missing, make a site completely inaccessible to certain users. Examples include: all images have alt text, all form fields have labels, content does not flash more than three times per second, keyboard navigation is possible.

Level AA adds criteria that address broader usability. This is where Canadian law typically sets its requirements. Key AA criteria include: colour contrast of at least 4.5:1 for normal text, text can be resized up to 200% without loss of content, focus is visible when navigating by keyboard, error suggestions are provided when input fails, and your site works when the browser is zoomed in.

Level AAA represents the highest standard. Many AAA criteria are appropriate for specific types of content — extended audio description for video, sign language interpretation — and applying them universally is not realistic. However, some AAA criteria are achievable on a standard website and are worth targeting, particularly the enhanced contrast ratio of 7:1 for body text. This is what this site targets for all body text, because 4.5:1 is often not enough for users with moderate vision loss.

What Canadian law actually requires

Canada does not have a single national web accessibility law covering all businesses. What exists is a patchwork of legislation at federal and provincial levels.

The Accessible Canada Act, in force since 2019, applies to federally regulated organizations — banks, airlines, telecommunications companies, broadcasters, and federal government departments. It does not directly set a technical standard in its text, but the Canadian Radio-television and Telecommunications Commission (CRTC) and other regulators have issued guidance referencing WCAG 2.1 Level AA.

Ontario's Accessibility for Ontarians with Disabilities Act (AODA) is the strongest provincial law currently in force. Its web content accessibility requirements apply to private sector organizations with 50 or more employees. The required standard is WCAG 2.0 Level AA (excluding live captions and audio descriptions). Organizations with fewer than 50 employees are not legally required to comply, but the standard is still considered best practice.

British Columbia's Accessible BC Act (2021) and the ongoing development of the province's accessibility standards will eventually create requirements for BC organizations, though as of mid-2026 the specific web standards are still being developed by the accessibility standards committee.

Quebec's Act Respecting Equal Access for Persons with Disabilities applies to public bodies. Private companies in Quebec are not currently required to meet WCAG under provincial law, though Quebec's broader human rights framework may still create obligations.

The practical takeaway for most Canadian small businesses: you may not have a legal requirement today, but accessibility law in Canada is moving in one direction, the AODA has teeth and applies to Ontario companies of meaningful size, and courts have found accessibility failures to constitute discrimination under human rights legislation even where no specific accessibility law applied. Building accessible now is cheaper than retrofitting later.

The most common failures on Canadian business sites

Accessibility audits of business websites consistently turn up the same problems. If you address these, you will be ahead of the vast majority of Canadian business sites.

Missing or empty alt text on images. Every image that conveys information needs a description. Images that are purely decorative should have alt="" so screen readers know to skip them. Product images, team photos, diagrams, and icons that serve a function all need descriptive alt text.

Insufficient colour contrast. Light grey text on white, or coloured text on a coloured background, frequently fails the 4.5:1 minimum ratio required by WCAG AA. This is one of the most common failures and one of the most harmful for users with any degree of vision loss.

No visible focus indicator. When keyboard users navigate through a page, they need to see which element currently has focus. Many websites override the browser's default focus outline with outline: none for aesthetic reasons — this makes the site unusable for keyboard-only users.

Form fields without labels. Placeholder text inside a form field disappears when you type. Users with memory difficulties or screen reader users relying on labels cannot use a form that only provides placeholder text as its label.

Links that say "click here" or "read more." Screen reader users often navigate between links without reading the surrounding context. A link that says "read more" tells them nothing about where it goes. Links should describe their destination: "Read our accessibility statement" not "Read more."

Keyboard traps. Modal dialogs, dropdown menus, and custom components that capture keyboard focus without providing a way to exit with the keyboard create traps for keyboard-only users.

Low vision specifically: what most guides miss

Low vision is one of the most common disability categories — far more common than blindness — and it is chronically underserved by accessibility guidance, which tends to focus on screen reader users (who are typically blind or have very significant vision loss).

Low vision users often use magnification software, enlarged system fonts, or browser zoom rather than screen readers. This creates a specific set of requirements that are easy to overlook.

Reflow at 400% zoom. WCAG 2.1 added a criterion (1.4.10) requiring that content reflows at 400% zoom without horizontal scrolling. If your site breaks when someone zooms in heavily on a mobile-style viewport, it fails this criterion. Most modern responsive sites pass this if they are built properly, but many older sites and sites using fixed-width layouts fail it.

Text spacing. WCAG 2.1 criterion 1.4.12 requires that no information or functionality is lost when text is customized — increased line height, letter spacing, word spacing, or paragraph spacing. Sites that break layout when users apply custom stylesheets or browser accessibility settings fail this test.

Minimum font size. WCAG does not set a minimum font size, but the implied baseline from the contrast criteria at AA (4.5:1 for normal text, 3:1 for large text, where large is defined as 18pt/24px or 14pt/18.67px bold) means that tiny text carries a higher contrast burden. The practical guidance for low vision readability is a 16px minimum body text, with 18–20px preferred. This site uses 20px as its root font size.

Font choice. Not all fonts are equally legible at small sizes or under magnification. Fonts designed for legibility — including Atkinson Hyperlegible, created by the Braille Institute specifically for low vision readers — perform significantly better than decorative display fonts used at body sizes. Inter, Source Sans, and similar humanist sans-serif fonts are also strong performers.

Where to start if your site is not accessible yet

A full WCAG audit requires someone who knows what they are doing — either a specialist or a developer with accessibility experience. But there are practical first steps any site owner can take right now.

Run your site through the WAVE Web Accessibility Evaluation Tool from WebAIM — a free browser extension that flags common errors. It will not find everything, but it will surface the obvious problems quickly.

Check your contrast ratios using the WebAIM Contrast Checker. Paste in your text colour and background colour and see your ratio. If you are below 4.5:1 for any body text, that is a priority fix.

Tab through your own website using only the keyboard. Can you reach every link and button? Can you see where you are at all times? Can you escape any popups or menus? If you get stuck anywhere, that is a failure that affects real users.

Turn images off in your browser and see if your site still makes sense. Every image that carried information you now cannot access is a missing alt text problem.

Zoom your browser to 200% and then 400%. Does the layout hold? Can you still read everything? Does anything disappear or overlap?