What's the Difference Between ADA and WCAG? Standards Explained

When people start learning about web accessibility, the acronyms can be overwhelming. ADA, WCAG, Section 508, EAA—what do these mean and how do they relate? Two terms you'll encounter constantly are ADA and WCAG, and understanding the difference between them is fundamental to getting accessibility right.

Here's the core distinction: ADA is a law that requires accessibility. WCAG is a technical standard that defines what accessibility means. The law tells you that you must be accessible; the standard tells you how.

Let me unpack this in practical terms.

Q: What's the difference between ADA and WCAG?

A: The ADA (Americans with Disabilities Act) is a US civil rights law prohibiting discrimination against people with disabilities, including in digital spaces. WCAG (Web Content Accessibility Guidelines) is an international technical standard defining specific accessibility requirements. The ADA mandates accessibility; WCAG specifies how to achieve it. Courts and regulations increasingly reference WCAG as the technical measure of ADA compliance.

Understanding the ADA

What the ADA Is

The Americans with Disabilities Act is a US federal civil rights law passed in 1990. It prohibits discrimination against people with disabilities in several areas:

Title I: Employment Title II: State and local government services Title III: Places of public accommodation (businesses open to the public) Title IV: Telecommunications Title V: Miscellaneous provisions

For web accessibility, Title III is most relevant—it requires businesses open to the public to provide equal access to their goods and services.

How the ADA Applies to Websites

The ADA doesn't specifically mention websites—it was written before the web existed. However:

Courts have interpreted the ADA to cover websites, particularly when connected to physical business operations or when the website is the primary means of accessing services.

The Department of Justice has consistently stated that the ADA applies to websites and published guidance in 2022 affirming this position.

Legal precedent through cases like Robles v. Domino's Pizza has established that website accessibility is required under the ADA.

What the ADA Requires

The ADA is principles-based, not prescriptive. It requires that people with disabilities have "full and equal enjoyment" of goods and services. For websites, this means:

• Users with disabilities must be able to access the same information as other users
• Barriers preventing access violate the law
• Businesses must remove barriers or provide alternatives

The ADA doesn't specify technical requirements like "images must have alt text" or "contrast must be 4.5:1." It establishes the legal obligation; technical standards fill in the details.

ADA Enforcement

The ADA is enforced primarily through:

Private lawsuits: Individuals can sue businesses for accessibility violations. This is the primary enforcement mechanism for web accessibility, resulting in thousands of lawsuits annually.

DOJ enforcement: The Department of Justice can bring enforcement actions, though private litigation is more common.

Settlement agreements: Many cases settle with accessibility remediation commitments and monetary payments.

Understanding why businesses get sued helps contextualize ADA enforcement.

Understanding WCAG

What WCAG Is

The Web Content Accessibility Guidelines (WCAG) are technical standards developed by the World Wide Web Consortium (W3C). They define specific, testable requirements for making web content accessible.

WCAG is international—not US-specific—and has become the global reference standard for web accessibility.

WCAG Structure

WCAG is organized around four principles (POUR):

Perceivable: Information must be presentable in ways users can perceive Operable: Interface must be operable by users Understandable: Information and operation must be understandable Robust: Content must work with assistive technologies

Under each principle are guidelines, and under guidelines are success criteria—specific, testable requirements.

WCAG Versions

WCAG has evolved through versions:

WCAG 2.0 (2008): Original version, still referenced in some regulations WCAG 2.1 (2018): Added criteria for mobile, cognitive, and low vision accessibility WCAG 2.2 (2023): Current version with additional criteria

Each version is backward-compatible—conforming to 2.2 means you also conform to 2.1 and 2.0.

WCAG Conformance Levels

Success criteria are assigned conformance levels:

Level A: Essential requirements Level AA: Standard target for most compliance needs Level AAA: Enhanced accessibility

Understanding conformance levels helps you determine appropriate targets.

WCAG Requirements Examples

WCAG provides specific, testable requirements:

1.1.1 Non-text Content (Level A): Images need text alternatives 1.4.3 Contrast (Level AA): Text needs 4.5:1 contrast ratio 2.1.1 Keyboard (Level A): All functionality must work with keyboard 2.4.4 Link Purpose (Level A): Link purpose must be determinable

These concrete requirements tell developers exactly what to implement.

How ADA and WCAG Work Together

The Practical Relationship

The ADA creates legal obligation; WCAG provides technical specification for meeting it.

In lawsuits: Plaintiffs typically allege ADA violation and cite specific WCAG failures as evidence. "The website violates the ADA because images lack alt text, violating WCAG 2.1 criterion 1.1.1."

In settlements: Consent decrees almost universally specify WCAG conformance levels. "Defendant will achieve WCAG 2.1 Level AA conformance within 24 months."

In DOJ guidance: The 2022 DOJ guidance on web accessibility explicitly references WCAG as the technical standard.

WCAG as ADA's Technical Standard

While the ADA doesn't formally adopt WCAG, the practical reality is that WCAG has become the de facto technical standard for ADA compliance:

• Courts reference WCAG in decisions
• Settlements require WCAG conformance
• DOJ guidance cites WCAG
• Expert witnesses evaluate against WCAG
• Accessibility professionals use WCAG as their framework

Achieving WCAG 2.1 or 2.2 Level AA conformance is the accepted path to ADA compliance for websites.

Important Distinctions

WCAG conformance doesn't guarantee immunity from ADA lawsuits. Someone can still file a lawsuit, and some WCAG criteria require interpretation. However, genuine WCAG conformance dramatically reduces legal risk and provides strong defense.

ADA compliance can theoretically exist without formal WCAG conformance. If your site is genuinely accessible to people with disabilities, you might satisfy ADA even without formally meeting every WCAG criterion. In practice, WCAG conformance is how this is demonstrated.

WCAG is more specific than ADA. The ADA requires "accessibility" broadly; WCAG defines 50+ specific testable criteria at the AA level alone.

Other Related Standards and Laws

Section 508

Section 508 of the Rehabilitation Act requires federal agencies to make technology accessible. Unlike the ADA, Section 508 formally incorporates WCAG (version 2.0) in its technical requirements.

Section 508 affects:

• Federal government agencies
• Federal contractors
• Organizations receiving federal funding

European Accessibility Act (EAA)

The EAA is European legislation requiring accessibility for various products and services, effective June 2025. It references EN 301 549, which incorporates WCAG 2.1.

US companies serving EU customers must consider EAA requirements.

State Laws

Some US states have additional accessibility laws:

California: Unruh Civil Rights Act interpreted to cover websites New York: State human rights law used alongside ADA

These generally align with ADA/WCAG framework rather than creating entirely different standards.

What This Means for Your Organization

If You're Based in the US

You're subject to the ADA if you're a business open to the public (Title III).

Target WCAG 2.2 Level AA as your compliance standard. This addresses current requirements and positions you for evolving expectations.

Document your efforts to demonstrate good faith compliance in case of legal challenges.

If You Sell to Government

Section 508 applies to federal sales. You'll need VPAT documentation demonstrating WCAG conformance.

If You Serve EU Customers

EAA requirements apply from June 2025. EN 301 549 (which includes WCAG) is the relevant standard.

Practical Compliance Path

1. Understand your obligations: ADA applies to most US businesses; WCAG provides the technical specification
2. Assess current state: Get an accessibility scan to understand your issues
3. Remediate against WCAG: Fix issues based on WCAG success criteria
4. Maintain compliance: Ongoing monitoring ensures you don't regress
5. Document everything: Records of compliance efforts support legal defense

Common Questions About ADA vs. WCAG

"Do I need to comply with both?"

You need to comply with the ADA (assuming you're a covered entity). Complying with WCAG is how you demonstrate ADA compliance. They're not separate requirements—WCAG is the technical implementation of ADA's accessibility mandate.

"Which version of WCAG matters?"

WCAG 2.1 AA is currently referenced in most legal contexts. WCAG 2.2 AA is the current version and increasingly expected. Target 2.2 AA to meet both current and emerging requirements.

"What about mobile apps?"

Both ADA and WCAG apply to mobile apps. ADA doesn't distinguish between web and mobile. WCAG 2.1 added criteria specifically addressing mobile accessibility.

"Is WCAG AAA required?"

Not typically. WCAG AA is the standard target. Some AAA criteria aren't achievable for all content types. However, adopting specific AAA criteria where practical provides enhanced accessibility.

FAQ Section

Q: Can I be sued for ADA violations even if I meet WCAG standards?

A: Technically yes—someone can file a lawsuit regardless of your compliance status. However, genuine WCAG conformance provides strong defense and dramatically reduces lawsuit likelihood. Most accessibility lawsuits target sites with obvious, significant violations.

Q: Does WCAG apply outside the United States?

A: Yes, WCAG is an international standard used worldwide. Different countries reference it through their own laws (EAA in Europe, AODA in Ontario, etc.). WCAG itself isn't a law—it's the technical standard laws reference.

Q: Is there certification for ADA or WCAG compliance?

A: There's no official certification body. Organizations can self-declare conformance, commission third-party audits, or produce VPATs. Professional accessibility audits provide credible assessment documentation.

Q: How often do WCAG requirements change?

A: WCAG versions release years apart (2008, 2018, 2023). Changes add new criteria without modifying existing ones. Organizations should plan to adopt new versions but have time to do so—the standard is stable.

Q: If I use an accessibility overlay, does that satisfy ADA requirements?

A: No. Overlay widgets don't achieve WCAG conformance and have been specifically rejected in legal proceedings. They don't satisfy ADA requirements regardless of marketing claims.

Understanding the Framework

The ADA-WCAG relationship is actually elegant once you understand it:

• ADA: "You must provide equal access to people with disabilities"
• WCAG: "Here's specifically what accessible web content looks like"

Legal obligation meets technical specification. Together, they create a framework that protects people with disabilities while giving businesses clear targets for compliance.

Ready to assess your accessibility status against these standards? Get a free accessibility scan to identify WCAG issues affecting your ADA compliance.

Related Articles:

• What Are the Legal Requirements for Website Accessibility?
• WCAG Conformance Levels: A, AA, or AAA?
• Why Am I Getting Sued for Website Accessibility?

TestParty's content team produced this article using AI-powered research tools combined with our expertise in automated accessibility testing. The guidance here reflects current best practices but shouldn't substitute for professional legal counsel on ADA or WCAG compliance matters.