Quick Answer
WCAG is a technical guideline, not a law, that defines what makes digital content accessible. Section 508 is a U.S. federal law requiring federal agencies’ own technology to meet WCAG 2.0 Level AA specifically. The ADA is a broader civil rights law with two different tracks: Title II now requires state and local government websites to meet WCAG 2.1 AA under a 2024 federal rule, while Title III, covering private businesses, has no codified technical standard and relies mainly on litigation that has converged on WCAG 2.1 AA in practice.
Introduction
In the same conversation, a procurement officer asks for something “508 compliant,” a vendor promises their product is “ADA compliant,” and someone else says just “meet WCAG AA” and everyone will be fine. These three phrases get used as if they mean the same thing. They don’t, and treating them as interchangeable is exactly how organizations end up meeting one requirement while missing another entirely.
One of them is a technical guideline. The other two are laws, and those two laws don’t even work the same way as each other, let alone point to the same version of the guideline.
That last part is the detail most comparisons skip entirely. Section 508 and the ADA reference different WCAG versions, and one part of the ADA doesn’t reference a specific WCAG version at all. Getting this wrong matters, since it changes what an organization actually needs to test against and what its real legal exposure looks like.
This is also increasingly urgent. Digital accessibility litigation remains an important compliance consideration, the compliance deadlines under the ADA’s newest rule are approaching, and the private-sector side of the ADA remains in a genuinely unresolved regulatory state, closer to case law than to a fixed checklist. This guide explains what each framework actually is, who it applies to, which WCAG version it requires if any, and how they relate to each other, so the answer to “are we compliant” can be based on the actual applicable rule rather than a phrase borrowed from a different one.
What Is WCAG?
The Web Content Accessibility Guidelines, published by the W3C, are a technical guideline that defines what makes digital content accessible, organized around four principles: content should be perceivable, operable, understandable, and robust. Each version builds success criteria around those principles, grouped into conformance levels A, AA, and AAA. WCAG is not a law.
It has no enforcement mechanism of its own, no inspector, no court, no penalty written into the document itself. It becomes legally significant only when a specific law or regulation references it, and, as the next two sections show, different laws reference different versions of it, which is exactly where most of the real confusion in this comparison comes from.
What Is Section 508?
Who it applies to
Section 508 is part of the U.S. Rehabilitation Act of 1973. It requires federal agencies to make the information and communication technology they develop, procure, maintain, or use accessible to people with disabilities. This includes federal websites, internal software, and electronic documents, and it extends to vendors selling technology to federal agencies through procurement requirements, since an agency cannot buy inaccessible technology and call the agency itself compliant. Federal procurement can also require vendors to provide accessibility conformance information about their products.
Which WCAG version it actually requires
Section 508’s technical standard, updated in a 2017 refresh that took effect in 2018, specifically incorporates WCAG 2.0 Level AA, not WCAG 2.1 or 2.2. Many federal agencies now expect vendors to build to WCAG 2.1 or 2.2 AA in practice, since newer versions are backward compatible with 2.0, but that is a procurement preference, not the letter of the actual regulation.
A vendor citing “Section 508 compliance” should confirm which WCAG version their own conformance claim is actually based on, since a report written against an older version can still be accurate while quietly understating what a specific agency now expects.
What Is the ADA, and Why Are Title II and Title III Different?
The Americans with Disabilities Act is a civil rights law, not a technology standard, and it covers far more than websites. For digital accessibility specifically, its two most relevant sections work in genuinely different ways.
ADA Title II: state and local government
Title II covers state and local government entities, everything from a city’s own website to a public university’s online course portal. In April 2024, the Department of Justice finalized a rule requiring state and local government websites and mobile apps to meet WCAG 2.1 Level AA, the first time DOJ adopted a specific technical standard in a Title II regulation rather than leaving accessibility to case-by-case interpretation. The compliance deadlines were later extended, giving larger government entities until April 2027 and smaller entities and special districts until April 2028. The rule also applies even where a government entity has a private vendor build or host the digital experience on its behalf.
ADA Title III: private businesses
Title III covers private businesses that serve the public, from e-commerce sites to a local restaurant’s online ordering system. DOJ’s own guidance, published in March 2022, states that the Department has “consistently taken the position” that the ADA applies to the websites of businesses open to the public. That guidance page itself notes plainly that it does not reflect the newer Title II requirements published in 2024, because those requirements do not apply to Title III. No equivalent Title III regulation exists. There is no codified technical standard for private business websites under the ADA, despite DOJ having explored the idea through rulemaking efforts over the years.
Enforcement runs almost entirely through litigation and settlements, which have converged on WCAG 2.1 AA as the practical benchmark courts and plaintiffs’ attorneys typically cite, without that number being a legal requirement written into a regulation. This is the single biggest source of confusion in this whole comparison: a business can be sued successfully under Title III for an inaccessible website without any regulation ever having specified what “accessible” technically means.
Section 508 vs ADA vs WCAG: The Real Difference at a Glance
| Framework | What It Is | Who It Applies To | WCAG Version | Legal Mechanism |
|---|---|---|---|---|
| WCAG | Technical guideline | Anyone who chooses to follow it | N/A, itself the standard | None on its own but referenced by various laws |
| Section 508 | Federal law | Federal agencies and their vendors | WCAG 2.0 AA | Codified regulation |
| ADA Title II | Civil rights law | State and local government | WCAG 2.1 AA | Codified regulation (2024 rule) |
| ADA Title III | Civil rights law | Private businesses open to the public | None codified | Litigation and settlements |
Does Meeting WCAG Satisfy Section 508 or the ADA?
It depends entirely on which WCAG version and which framework. Meeting WCAG 2.0 AA satisfies Section 508’s actual codified requirement. Meeting WCAG 2.1 AA satisfies ADA Title II’s codified requirement, and since 2.1 is backward compatible with 2.0, it also covers Section 508. For ADA Title III, there is no codified requirement to “satisfy” in the same sense, so strong WCAG 2.1 AA conformance reduces litigation risk without functioning as a guaranteed legal shield, since a court is evaluating the underlying civil rights obligation, not a specific technical checklist, and a technically WCAG-conformant site could still face a claim if a specific interaction genuinely excludes someone in practice.
An organization subject to more than one of these frameworks should not assume that meeting the most familiar one automatically covers the others, and should not assume that a WCAG conformance report alone is the same thing as a formal legal compliance determination for whichever law actually applies.
What Should an Organization Actually Do?
Start by identifying which framework or frameworks actually apply, based on whether the organization is a federal agency, works under a federal procurement requirement, is a state or local government entity, or is a private business, since more than one can apply at once, a state university, for instance, can face both Title II obligations as a government entity and federal funding conditions that pull in Section 508.
Next, identify the specific technical requirements and WCAG version tied to each applicable framework, rather than assuming one number covers everything, a federal contractor building software for a state agency may need to satisfy Section 508’s 2.0 AA baseline and that agency’s own newer internal standard at the same time.
Then test against those requirements using a mix of automated and manual methods, since automated tools catch common issues quickly but cannot judge whether an experience genuinely works for someone using assistive technology. Remediate what testing finds, document the findings and the fixes in a form that can be shown to an auditor or a court if needed, and retest afterward, since a single pass does not confirm a fix actually resolved the problem. For organizations facing more than one framework, look specifically for where the requirements overlap rather than assuming full conformance with one automatically satisfies another.
If you’re working through which of these frameworks applies to your organization, get in touch with BarrierBreak for accessibility guidance suited to your specific situation.
Frequently Asked Questions
Does meeting WCAG 2.2 AA satisfy Section 508?
WCAG 2.2 includes all of the WCAG 2.0 Level A and AA success criteria, so a site conforming to WCAG 2.2 AA also meets the WCAG 2.0 AA success-criterion baseline referenced by Section 508. However, Section 508 compliance can involve requirements beyond the WCAG success criteria, so organizations should assess the full applicable Section 508 requirements rather than treating WCAG conformance alone as a complete answer.
Is ADA Title III legally required to meet WCAG yet?
No specific WCAG version is codified into a Title III regulation. DOJ’s 2022 guidance confirms the ADA applies to business websites but sets no technical standard, and courts and settlements have converged on WCAG 2.1 AA as the practical benchmark rather than a written legal requirement.
Can a private company face an ADA lawsuit without a specific web regulation existing?
Yes. Title III litigation has proceeded for years without a codified technical standard, based on the ADA’s general requirement that businesses open to the public provide equal access to their goods and services, including online. Courts have generally sided with plaintiffs on the underlying question of whether the ADA applies to a business website at all, even while the specific technical bar remains unwritten in regulation.
Have the ADA Title II compliance deadlines actually changed?
Yes. The original 2024 rule set deadlines of April 2026 for larger government entities and April 2027 for smaller ones. Those were later extended by an additional year each, to April 2027 for larger entities and April 2028 for smaller entities and special districts, though the underlying WCAG 2.1 AA requirement itself did not change.
What if more than one accessibility framework applies to my organization?
Identify the specific technical requirements tied to each applicable framework rather than assuming one WCAG version automatically satisfies all of them, then test against the combined set of applicable requirements. The legal mechanism behind each framework, codified regulation versus litigation exposure, still needs to be tracked separately even where the technical requirements overlap.
Is Section 508 only about websites?
No. It covers information and communication technology broadly, including software, electronic documents, and hardware used, developed, procured, or maintained by federal agencies, not just public-facing websites. An internal agency tool that no member of the public ever sees is still subject to Section 508 if federal employees with disabilities need to use it.
Further Reading
