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What is WCAG, and why it matters for your SaaS

· 6 min read
The VeriWasp Team
The VeriWasp Team
Automated testing for indie SaaS

WCAG, the Web Content Accessibility Guidelines, is the standard that defines what it means for a website to be usable by people with disabilities. If you have ever wondered whether your SaaS is "accessible enough," WCAG is the yardstick almost everyone (including courts and procurement teams) actually measures against.

Here is what it is, how it is structured, and why it is worth caring about even before anyone forces you to.

What WCAG actually is​

WCAG is published by the W3C, the same standards body behind HTML and CSS. It is not a law and not a piece of software. It is a set of testable success criteria: concrete statements like "text has a contrast ratio of at least 4.5:1 against its background" or "every form control has a label." Laws and contracts around the world then point at WCAG as the definition of "accessible," which is why it has become the de facto global standard.

The version you want to target today is WCAG 2.1 (or 2.2, which adds a handful of criteria). WCAG 3.0 is in draft and years away from being the reference anyone requires.

The four principles: POUR​

Every WCAG criterion rolls up into one of four principles, easy to remember as POUR:

  • Perceivable. Users can perceive the content through some sense. Images need text alternatives, video needs captions, and color alone can never be the only way information is conveyed.
  • Operable. Users can operate the interface. Everything works with a keyboard, not just a mouse, and nothing traps focus or flashes in a way that could trigger seizures.
  • Understandable. Content and controls behave predictably. Form errors are explained in text, labels are clear, and the interface does not surprise the user.
  • Robust. The markup is clean enough that assistive technology (screen readers, switch devices, voice control) can interpret it reliably.

If you internalize nothing else, POUR is a good filter: when you build a new feature, ask whether someone could perceive it, operate it, understand it, and whether a screen reader could make sense of it.

The three levels: A, AA, AAA​

WCAG sorts its criteria into three conformance levels:

  • Level A is the floor. Failing these makes content genuinely unusable for some people (an image button with no label, a video with no captions at all).
  • Level AA is the practical target. It covers the things that make a site usable rather than merely possible to use: color contrast, resizable text, consistent navigation, visible focus, and clear error handling.
  • Level AAA is the gold standard, but it is not expected for a whole site. Some AAA criteria are impractical or even conflicting for certain content, so almost no one commits to full AAA.

When a law, a contract, or a customer says "must be accessible," they almost always mean WCAG 2.1 Level AA. That is the number to aim for.

Why it matters, beyond the checkbox​

Real people, more than you think​

Around one in five people has a disability of some kind, and that number understates the reach. Accessibility also covers temporary situations (a broken arm, bright sunlight on a phone screen) and permanent ones (low vision, color blindness, motor differences). Building for accessibility is building for a much larger slice of your users than the label suggests.

In the United States, the Americans with Disabilities Act has been applied to websites, and WCAG 2.1 AA is the benchmark courts and settlements reference. Web accessibility demand letters and lawsuits number in the thousands each year, and they increasingly target small companies, not just household names. Public sector and enterprise buyers go further: Section 508 in the US and EN 301 549 in the EU both require WCAG conformance, so an accessibility gap can quietly disqualify you from a deal before anyone even tells you why.

It overlaps with things you already care about​

Most accessibility work is also good engineering. Semantic HTML, meaningful alt text, proper headings, and labeled controls are exactly what search engines parse to understand your page, so accessibility and SEO pull in the same direction. Clear focus states, readable contrast, and predictable forms reduce support tickets and lift conversion for everyone, not only users with disabilities. Accessibility is rarely a tax you pay for a minority; it is usually a quality bar that helps the whole product.

What AA conformance looks like in practice​

You do not need to memorize the spec to get most of the way there. A large share of real-world failures come down to a short list:

  • Text and interactive elements meet contrast ratios (4.5:1 for normal text, 3:1 for large text and UI components).
  • Every image that carries meaning has alt text, and decorative images are marked so screen readers skip them.
  • Every form field has a programmatic label, not just a placeholder.
  • The whole interface works with a keyboard, and the focused element is always visible.
  • Headings describe the page structure in order, without skipping levels.
  • Links are distinguishable from surrounding text by more than color alone.

Get those right and you have cleared the majority of what an audit will flag.

How to check your own site​

You cannot fix what you cannot see, and manual review misses a lot. Automated tools catch the mechanical failures (contrast, missing alt text, unlabeled controls, heading order) quickly and consistently, which is the right first pass before any human review.

VeriWasp runs a real WCAG scan on every page it tests, and the free accessibility scanner will crawl your site and group its findings by rule, so "color contrast too low on 72 elements across 5 pages" reads as one issue to fix, not seventy-two. It is a fast, honest way to see where you actually stand against AA before you decide what to do about it.

Accessibility is not a one-time project you finish. It is a quality bar you hold as you ship. Knowing where you stand today is the first step.