Website Accessibility Standards: WCAG, ADA, EAA, Section 508, and AODA Explained
ADA Title III, the law covering private businesses in the US, has no government mandated compliance deadline for web accessibility. Enforcement is entir..
ADA Title III, the law covering private businesses in the US, has no government-mandated compliance deadline for web accessibility. Enforcement is entirely lawsuit-driven, and courts have settled on WCAG 2.1 AA as the de facto technical standard. That single fact already tells you something important: the rules governing your website do not always come with a clear deadline or a government body knocking on your door.
Video: Website Accessibility Standards: WCAG, ADA, EAA, Section 508, and AODA Explained
Most businesses encounter four or five acronyms, WCAG, ADA, EAA, Section 508, AODA, and cannot tell whether they need to comply with one, all of them, or none. That confusion is understandable. These are not competing standards. They are overlapping frameworks operating in different jurisdictions, each pointing back to the same underlying technical specification. The answer to “which ones apply to me?” depends entirely on who you are, where you operate, and who you sell to.
This article maps each standard, explains how they connect, and gives you a decision framework for identifying what actually governs your website. If you already know your applicable standard and want a baseline now, you can run a free accessibility scan against WCAG 2.1 AA criteria before reading further.
The Standards Landscape at a Glance
Here is the reference map. Each standard, its jurisdiction, its technical requirement, and how it is enforced.
| Standard | Jurisdiction | Who It Covers | Technical Requirement | Enforcement |
|---|---|---|---|---|
| WCAG 2.1 AA | Global (W3C specification) | Not a law – referenced by all other standards | WCAG 2.1 Level AA | No direct enforcement; laws reference it |
| ADA Title II | United States | State and local government entities | WCAG 2.1 Level AA | DOJ final rule; deadlines April 2027 / 2028 |
| ADA Title III | United States | Private businesses open to the public | WCAG 2.1 Level AA (de facto) | Lawsuit-driven; no government deadline |
| EAA | European Union | Businesses with 10+ employees or €2M+ turnover selling into the EU | WCAG 2.1 Level AA | National enforcement bodies; in force June 2025 |
| Section 508 | United States | Federal agencies and federally funded organisations | WCAG 2.0 Level AA (2.1 alignment in progress) | Federal procurement rules; agency audits |
| AODA (IASR) | Ontario, Canada | Ontario public sector and large private organisations (50+ employees) | WCAG 2.0 Level AA | Accessibility Directorate of Ontario; compliance audits |
Two things stand out. First, WCAG is not a law. It is the shared technical specification that every other entry in this table references. Second, the WCAG version required varies by jurisdiction: EAA and ADA courts use WCAG 2.1 AA, while Section 508 and AODA currently reference WCAG 2.0 AA. That distinction matters when you are running audits or writing compliance documentation.
WCAG: The Technical Foundation Every Standard Builds On
The Web Content Accessibility Guidelines (WCAG) are published by the World Wide Web Consortium (W3C), an international standards body. WCAG is not legislation. No government enforces it directly. What governments and courts do is point to it, which means understanding WCAG once gives you a working foundation for compliance across every jurisdiction in this article.
WCAG is organised around four principles (Perceivable, Operable, Understandable, Robust) and three conformance levels: A, AA, and AAA. Almost every legal standard targets Level AA, which addresses the most significant barriers for most users without requiring the edge-case provisions of AAA. For the full breakdown of those principles, conformance levels, and what changed in version 2.2, see WCAG 2.2 Explained in Plain English.
The version landscape matters here. WCAG 2.0 was published in 2008. WCAG 2.1 followed in 2018, adding 17 criteria covering mobile accessibility, low vision, and cognitive accessibility. WCAG 2.2 arrived in 2023 with 9 more. Most legal standards have not yet formally updated their WCAG reference, so you will encounter situations where the law cites WCAG 2.0 but courts or regulators expect at minimum WCAG 2.1. For any new accessibility work, target WCAG 2.1 AA. Where resources allow, move toward 2.2 AA.
ADA: What US Businesses Must Know About Website Compliance
The Americans with Disabilities Act (ADA) covers two distinct categories of organisation, and the rules differ for each.
ADA Title II covers state and local government entities: public schools, municipal websites, transit authorities, courts. In April 2024, the Department of Justice (DOJ) published a final rule requiring these entities to conform to WCAG 2.1 Level AA. The deadlines have since been extended by one year: entities serving populations over 50,000 must comply by April 24, 2027; smaller entities have until April 26, 2028. If you run a government website or work with a government client, these are hard deadlines backed by federal rule.
ADA Title III covers private businesses that operate as places of public accommodation: retailers, restaurants, hotels, professional services, and any company with a public-facing website. According to ADA.gov’s guidance on web accessibility, there is no government-mandated compliance deadline for private businesses. Enforcement is lawsuit-driven: a plaintiff files a complaint, the DOJ may get involved, or a private right of action proceeds in federal court. Courts have consistently applied WCAG 2.1 AA as the standard by which a website is judged accessible or not.
The practical implication: if you run a private business with a public website, you are not waiting for a deadline. The exposure exists now. Approximately 3,117 federal web accessibility lawsuits were filed in 2025, a 27% increase over 2024, and total cases including state filings exceeded 5,000, according to UsableNet’s 2025 Year in Review.
For the full compliance process, industry risk breakdown, and what to do if you receive a demand letter, see ADA Website Compliance: The Complete 2026 Guide.
EAA: What the European Accessibility Act Means If You Sell Into the EU
The European Accessibility Act (EAA) came into force on June 28, 2025. It requires businesses selling products or services in EU member states to meet WCAG 2.1 AA standards. According to the European Commission, it applies to any company with 10 or more employees or €2 million or more in annual turnover selling into EU markets, regardless of where that company is headquartered.
That last point catches many US and UK businesses off guard. If you have European customers through an e-commerce site with no physical EU presence, the EAA applies to you, provided you clear the size threshold. Micro-enterprises (fewer than 10 employees and under €2M turnover) are exempt, but that exemption does not extend to companies that grow past it.
The technical requirement is WCAG 2.1 Level AA, applied to digital products and services including websites, mobile apps, e-readers, and ticketing systems. Enforcement is handled by national accessibility authorities in each EU member state, so the exact enforcement mechanism varies by country. The standard, however, is uniform across the bloc.
If you sell into more than one EU country, you may face multiple national enforcement bodies. Non-compliance findings in one member state typically signal broader exposure. The practical first step is conforming to WCAG 2.1 AA centrally, then documenting your compliance against the EAA’s product-specific requirements.
Section 508: The Standard for Federal Agencies and Their Contractors
Section 508 of the Rehabilitation Act of 1973 (as amended) requires all US federal agencies and federally funded organisations to make their electronic and information technology (EIT) accessible. According to Section508.gov, the current required standard is WCAG 2.0 Level AA, with formal alignment to WCAG 2.1 in progress.
The coverage is more specific than ADA Title III. Section 508 applies to:
- Federal agencies creating or procuring digital content
- Contractors and vendors selling software, platforms, or digital services to federal agencies
- Organisations receiving federal funding for technology projects
If you are bidding on federal contracts or your product is used by a federal agency, Section 508 compliance is a procurement requirement, not just a risk consideration. Agencies must include Section 508 specifications in their procurement solicitations, and vendors are expected to provide a Voluntary Product Accessibility Template (VPAT), a standardised document describing how their product meets each criterion.
The current WCAG 2.0 AA baseline means Section 508 is technically less demanding than ADA court expectations, which use WCAG 2.1 AA. In practice, most federal procurement officers expect conformance that reflects current standards. Building to WCAG 2.1 AA covers you against both the existing rule and the direction of travel.
AODA: Web Accessibility Requirements for Ontario and Canada
The Accessibility for Ontarians with Disabilities Act (AODA), passed in 2005, establishes accessibility standards for organisations operating in Ontario. The web accessibility requirements fall under the Integrated Accessibility Standards Regulation (IASR), which specifies who must comply and by when.
The IASR requires organisations to make their websites and web content conform to WCAG 2.0 Level AA (with certain exceptions). The requirement applies differently depending on organisation type:
- Ontario public sector organisations (government bodies, hospitals, schools, universities) have been required to meet WCAG 2.0 AA for new and significantly refreshed content since January 1, 2014 for Level A and January 1, 2021 for Level AA.
- Large private and non-profit organisations with 50 or more employees operating in Ontario were required to meet WCAG 2.0 AA by January 1, 2021 for new and refreshed content.
Small private organisations (fewer than 50 employees) are subject to WCAG 2.0 Level A for new internet and intranet content published after January 1, 2014, but the full Level AA requirement does not apply to them under the IASR.
Enforcement sits with the Accessibility Directorate of Ontario, which audits organisations and can require remediation. Non-compliance can result in administrative monetary penalties.
If your business is incorporated or operates in Ontario, AODA applies. Canadian federal government organisations are also subject to separate requirements under the Accessible Canada Act (ACA), which references WCAG 2.1 AA as its target standard, though that legislation has its own compliance timelines and scope.
What Automated Scanning Can and Cannot Confirm Against These Standards
According to the WebAIM Million 2025 Annual Report, 94.8% of the top 1 million home pages contain detectable WCAG 2 A/AA failures. “Detectable” is the operative word. Automated tools find what automated tools can find, and that is a meaningful but bounded share of the full accessibility picture.
Here is what a Website Accessibility Checker (Free Tool) reliably detects:
- Colour contrast ratios: whether text and background combinations meet the WCAG 2.1 AA threshold of 4.5:1 for normal text and 3:1 for large text
- Missing or empty alt text: images without text alternatives, or images with alt attributes left blank where content is present
- Form label associations: whether form inputs have programmatically associated labels that assistive technology can read
- Document heading structure: whether heading levels (H1, H2, H3) are used in logical sequence or skipped arbitrarily
- Empty links and buttons: interactive elements with no discernible text that a screen reader can announce
- Missing language attributes: whether the page’s language is declared in code so assistive technology uses the correct pronunciation rules
- Basic keyboard focus indicators: whether focusable elements have a visible focus state in the page’s default CSS
What automated scanning cannot confirm:
- Logical reading order: whether content flows in a sequence that makes sense to someone navigating by keyboard or screen reader. That requires a human to actually navigate the page.
- Cognitive clarity: whether language is plain, instructions are clear, and error messages are helpful. Automated tools check for the presence of error messages, not their quality.
- Screen reader interaction quality: whether dynamic components (carousels, modals, custom dropdowns) behave correctly when operated with JAWS, NVDA, or VoiceOver.
- Multimedia alternatives: whether captions are accurate and synchronised, or whether audio descriptions convey meaningful visual information. Tools detect the presence of captions, not their correctness.
- Meaningful alt text: tools flag missing alt text, but cannot judge whether the alt text provided actually describes the image in a useful way.
The practical implication: automated scanning is a reliable first pass for the categories above, and it will surface the most common, most detectable failures. It cannot replace a manual audit for full WCAG conformance. For any legal standard that requires documented conformance, whether an EAA accessibility statement, a Section 508 VPAT, or a formal ADA compliance review, automated results are the starting point, not the finish line.
Which Standard Applies to You? A Decision Framework
Work through these questions in order. The first answer that applies defines your primary compliance obligation.
1. Are you a US state or local government entity, or do you operate a website on behalf of one? If yes: ADA Title II applies. Your deadline is April 2027 (large population) or April 2028 (small population). Target: WCAG 2.1 Level AA.
2. Are you a US federal agency, or does your product or service get sold to federal agencies? If yes: Section 508 applies. Current standard: WCAG 2.0 Level AA. Build to WCAG 2.1 AA to future-proof against the alignment update in progress.
3. Do you sell products or services to customers in EU member states, and does your organisation have 10 or more employees or €2M or more in annual turnover? If yes: the EAA applies, regardless of where you are headquartered. In force since June 28, 2025. Target: WCAG 2.1 Level AA.
4. Do you operate in Ontario, Canada, or serve Ontario-based customers, and do you have 50 or more employees? If yes: AODA IASR applies. Current requirement: WCAG 2.0 Level AA. Fewer than 50 employees: WCAG 2.0 Level A for new public-facing content.
5. Are you a private business with a public-facing website in the US? If yes: ADA Title III applies. There is no deadline, but enforcement is live and growing. Courts use WCAG 2.1 AA. This is your baseline.
Most businesses land in more than one category. A US e-commerce company with EU customers and a federal contractor relationship could face ADA Title III, EAA, and Section 508 simultaneously. The overlap is manageable because all three point toward the same target: WCAG 2.1 Level AA. Achieving that conformance level gets you most of the way across all three frameworks.
Document your work, maintain it as your site changes, and add human review for the elements automated tools cannot catch. The standards differ in their enforcement mechanisms and deadlines. The technical work is largely the same.
If you are ready to see where your site stands, a free website accessibility checker will scan against WCAG 2.1 A/AA criteria and show you the detectable failures. It is the practical first step before any audit, legal review, or remediation project.
This article is for general informational purposes and is not legal advice. If you face a specific compliance obligation or legal matter, consult a qualified attorney.