WCAG compliance levels and versions explained: A, AA, AAA and 2.0, 2.1, 2.2
Last reviewed October 26, 2026 · 12 min read
Short answer. WCAG is the W3C's set of web accessibility success criteria, organized into levels A, AA and AAA. Most laws and contracts point to Level AA, and WCAG 2.2 AA, the current version, includes everything in 2.1 AA (except the obsolete 4.1.1 Parsing) plus six additional AA or A criteria.
What WCAG is
The Web Content Accessibility Guidelines are published by the W3C. They are organized under four principles (perceivable, operable, understandable, robust) and made of testable success criteria. Each criterion has a number such as 1.4.3 (contrast) and a level.
The three levels
- Level A: the most basic requirements. Missing these blocks some people completely, for example images with no text alternative or controls that cannot be reached by keyboard.
- Level AA: the level most laws, procurement rules and courts refer to. It adds requirements such as text contrast and resizing text.
- Level AAA: the most demanding. The W3C itself notes that AAA cannot be required as a general policy for entire sites, because some content cannot meet every AAA criterion.
A page "conforms" to a level only if it meets every criterion at that level and below, so AA means A plus AA.
The versions
| Version | Published | What changed | Where it shows up |
|---|---|---|---|
| WCAG 2.0 | 2008 | The original standard most older laws reference. | Section 508 (U.S. federal ICT) incorporates WCAG 2.0 A and AA. |
| WCAG 2.1 | 2018 | Added criteria for mobile, low vision and cognitive disabilities (for example reflow, non-text contrast, text spacing). | DOJ Title II web rule, and EN 301 549 v3.2.1 used with the European Accessibility Act. |
| WCAG 2.2 | 2023 | Added nine criteria and removed 4.1.1 Parsing as obsolete. | The current W3C Recommendation; the sensible target for new work. |
What is new in WCAG 2.2
WCAG 2.2 added these success criteria, of which the first five matter for most business sites at Level A or AA:
- 2.4.11 Focus Not Obscured (Minimum), AA: a focused element must not be completely hidden, for example behind a sticky header.
- 2.5.7 Dragging Movements, AA: anything that works by dragging needs a single-pointer alternative.
- 2.5.8 Target Size (Minimum), AA: pointer targets are at least 24 by 24 CSS pixels, with exceptions. See the target size guide.
- 3.2.6 Consistent Help, A: help options appear in the same place across pages.
- 3.3.7 Redundant Entry, A: do not make people re-enter information they already gave in the same process.
- 3.3.8 Accessible Authentication (Minimum), AA: logins must not rely only on a cognitive test such as remembering a password or solving a puzzle.
- 2.4.12, 2.4.13 and 3.3.9 are Level AAA.
The four principles, with everyday examples
Every WCAG criterion belongs to one of four principles. The initials spell POUR, which is an easy way to remember them.
- Perceivable. People must be able to take in the information. A product photo needs a text description for someone who cannot see it, and a video needs captions for someone who cannot hear it.
- Operable. People must be able to use the controls. Everything that works with a mouse should also work with a keyboard, and buttons should be large enough to hit.
- Understandable. Content and behavior must be clear. A form should say what it needs, and an error message should say what went wrong and how to fix it.
- Robust. The page must work with different browsers and assistive technology. A custom menu needs a name, a role and a state that a screen reader can announce.
How WCAG defines conformance
To claim that a page conforms to a level, WCAG sets five requirements. Most business owners never need the formal wording, but knowing the gist explains why "mostly conforms" is a weak claim.
- Level. The page meets every success criterion at that level and all lower levels. Level AA therefore includes all of Level A.
- Full pages. Conformance applies to a whole page, not part of one. You cannot exclude the awkward section.
- Complete processes. If a page is one step in a process, such as a checkout, every step in the process must conform.
- Only accessibility-supported ways of using technologies. The features you rely on must work with the assistive technology people actually use.
- Non-interference. Technologies that do not meet the criteria must not break the parts that do.
WCAG also allows a statement of partial conformance, for example when part of a page comes from a third party. That is the honest way to describe a site that is still being fixed.
The Level A and AA criteria in plain language
This table lists the WCAG 2.2 criteria at Levels A and AA, in the order W3C numbers them. Criteria marked 2.2 are new in that version. WCAG 2.2 removed 4.1.1 Parsing because modern browsers and assistive technology no longer depend on it. The wording here is a summary; the W3C Understanding documents give the full text and examples.
| Number and name | Level | In plain terms |
|---|---|---|
| 1.1.1 Non-text Content | A | Images and other non-text content have a text alternative. |
| 1.2.1 Audio-only and Video-only (Prerecorded) | A | Give a transcript or equivalent for audio-only and silent video. |
| 1.2.2 Captions (Prerecorded) | A | Videos with sound have captions. |
| 1.2.3 Audio Description or Media Alternative (Prerecorded) | A | Describe important visual information in video, or provide a text version. |
| 1.2.4 Captions (Live) | AA | Live video with sound has captions. |
| 1.2.5 Audio Description (Prerecorded) | AA | Prerecorded video has audio description. |
| 1.3.1 Info and Relationships | A | Structure shown on screen, such as headings, lists, tables and labels, is also in the code. |
| 1.3.2 Meaningful Sequence | A | The reading order makes sense. |
| 1.3.3 Sensory Characteristics | A | Instructions do not rely only on shape, color, size or position. |
| 1.3.4 Orientation | AA | Content works in both portrait and landscape. |
| 1.3.5 Identify Input Purpose | AA | Fields for personal details identify their purpose so browsers can fill them. |
| 1.4.1 Use of Color | A | Color is not the only way to show information. |
| 1.4.2 Audio Control | A | Audio that plays automatically for more than three seconds can be paused or stopped. |
| 1.4.3 Contrast (Minimum) | AA | Text contrast is at least 4.5 to 1, or 3 to 1 for large text. |
| 1.4.4 Resize Text | AA | Text can be enlarged to 200 percent without losing content. |
| 1.4.5 Images of Text | AA | Use real text, not pictures of text, where possible. |
| 1.4.10 Reflow | AA | Content fits a 320 pixel wide view without sideways scrolling. |
| 1.4.11 Non-text Contrast | AA | Controls and meaningful graphics have at least 3 to 1 contrast. |
| 1.4.12 Text Spacing | AA | Nothing breaks when users increase line, paragraph, letter and word spacing. |
| 1.4.13 Content on Hover or Focus | AA | Popups from hover or focus can be dismissed, hovered over and stay visible. |
| 2.1.1 Keyboard | A | Everything can be done with a keyboard. |
| 2.1.2 No Keyboard Trap | A | Focus can always move away from any element. |
| 2.1.4 Character Key Shortcuts | A | Single-key shortcuts can be turned off or remapped. |
| 2.2.1 Timing Adjustable | A | Time limits can be extended or turned off. |
| 2.2.2 Pause, Stop, Hide | A | Moving or auto-updating content can be paused. |
| 2.3.1 Three Flashes or Below Threshold | A | Nothing flashes more than three times in a second. |
| 2.4.1 Bypass Blocks | A | Users can skip repeated blocks such as the navigation. |
| 2.4.2 Page Titled | A | Each page has a descriptive title. |
| 2.4.3 Focus Order | A | Focus moves in an order that keeps the meaning. |
| 2.4.4 Link Purpose (In Context) | A | The purpose of each link is clear from its text or context. |
| 2.4.5 Multiple Ways | AA | There is more than one way to find a page, such as navigation and search. |
| 2.4.6 Headings and Labels | AA | Headings and labels describe their topic or purpose. |
| 2.4.7 Focus Visible | AA | The keyboard focus indicator is visible. |
| 2.4.11 Focus Not Obscured (Minimum) (2.2) | AA | A focused item is not completely hidden by other content. |
| 2.5.1 Pointer Gestures | A | Gestures that need several fingers or a path have a single-pointer alternative. |
| 2.5.2 Pointer Cancellation | A | Actions do not fire on the first press, or can be aborted or undone. |
| 2.5.3 Label in Name | A | A control's accessible name includes its visible label. |
| 2.5.4 Motion Actuation | A | Shake or tilt controls have alternatives and can be turned off. |
| 2.5.7 Dragging Movements (2.2) | AA | Anything done by dragging can also be done without dragging. |
| 2.5.8 Target Size (Minimum) (2.2) | AA | Pointer targets are at least 24 by 24 CSS pixels, with exceptions. |
| 3.1.1 Language of Page | A | The page language is set in the code. |
| 3.1.2 Language of Parts | AA | Passages in another language are marked. |
| 3.2.1 On Focus | A | Moving focus to an element does not cause an unexpected change. |
| 3.2.2 On Input | A | Changing a field does not cause an unexpected change. |
| 3.2.3 Consistent Navigation | AA | Repeated navigation appears in the same order. |
| 3.2.4 Consistent Identification | AA | Things that do the same job have the same label. |
| 3.2.6 Consistent Help (2.2) | A | Help options appear in the same place across pages. |
| 3.3.1 Error Identification | A | Errors are identified in text. |
| 3.3.2 Labels or Instructions | A | Fields have labels or instructions. |
| 3.3.3 Error Suggestion | AA | When known, the error message suggests a fix. |
| 3.3.4 Error Prevention (Legal, Financial, Data) | AA | Important submissions can be checked, corrected or reversed. |
| 3.3.7 Redundant Entry (2.2) | A | People are not asked to re-enter information they already gave in the same process. |
| 3.3.8 Accessible Authentication (Minimum) (2.2) | AA | Logging in does not depend only on remembering or solving something. |
| 4.1.2 Name, Role, Value | A | Custom controls expose a name, role and state to assistive technology. |
| 4.1.3 Status Messages | AA | Status updates can be announced without moving focus. |
Techniques, failures and how to use them
WCAG itself states what must be true. Separate W3C documents explain how to get there. Sufficient techniques are known ways to meet a criterion. Advisory techniques go further. Failures are documented patterns that do not meet a criterion, such as removing the focus outline with no replacement. When a scan reports a problem, the Understanding page for that criterion is the best place to read what it means and how to fix it.
How WCAG connects to the rules you may face
| Rule or standard | WCAG version it points to | Who it applies to |
|---|---|---|
| ADA Title II web rule | 2.1 Level AA | State and local governments |
| Section 508 | 2.0 Level A and AA | U.S. federal agencies and their technology purchases |
| EN 301 549 v3.2.1 (European Accessibility Act) | 2.1 Level AA | Covered products and services sold in the EU |
| ADA Title III | None specified | Businesses open to the public |
| Many contracts and procurement policies | Often 2.1 or 2.2 AA | Vendors selling to governments, schools and large companies |
Because WCAG 2.2 AA includes the 2.1 and 2.0 AA criteria, building to 2.2 AA meets all of these baselines, with the one exception that 4.1.1 Parsing, required by the older versions, no longer appears in 2.2. Browsers and assistive technology no longer rely on it, so this has little practical effect.
What about WCAG 3.0?
The W3C is developing a future set of guidelines, often called WCAG 3.0, as a working draft. It is not a replacement for WCAG 2 today, and laws and contracts still reference WCAG 2.0, 2.1 and 2.2. Work you do to meet 2.2 AA is not wasted when new guidance arrives.
To see how a real page measures up against the criteria that automation can test, a WCAG accessibility checker reports each finding with its criterion and the element involved.
Which should you target?
Aim for WCAG 2.2 Level AA. It satisfies the 2.1 AA standard that the DOJ requires of governments and that the European Accessibility Act's harmonised standard references, and it is the current version if a court or customer asks what you followed. If a contract names a specific version, meet that version.
Clir's checks map confirmed findings to WCAG success criteria at Level A and AA up to 2.2. No automated tool covers every criterion, because many need human judgment. See how Clir tests.
Common questions
Is WCAG a law?
No. WCAG is a technical standard. Laws and contracts can adopt it, as the DOJ did for government websites and as Section 508 does for federal technology. See the ADA checklist for how it applies to private businesses.
Do I need to meet Level AAA?
Generally not. Most laws and policies target Level AA. Some AAA criteria are good practice where they fit your content.
Is WCAG compliance required by law?
WCAG is a standard, not a law. Some laws adopt it: the DOJ's Title II rule requires WCAG 2.1 AA for state and local governments, and Section 508 incorporates WCAG 2.0. For private businesses under the ADA, no regulation names a version, though WCAG is widely used as the benchmark. See the ADA checklist.
What is a WCAG 2.2 checklist?
It is the list of success criteria you test against, usually Level A and AA. The table above is a plain-language version. Test each criterion on representative pages and record the result and the date.
Can a whole website be given an official WCAG conformance rating?
Conformance is defined per page and per process, and no automated tool or badge can confirm it for a whole site. A person or organization can make a conformance claim after evaluating the pages, and the claim should say which pages and which version were evaluated.
Do I need to meet Level AAA?
Generally not. The W3C recommends against requiring AAA for entire sites because some content cannot meet every AAA criterion. Many AAA criteria are still worth adopting where they fit.
What is WCAG compliance?
It means a page meets the success criteria of a chosen WCAG version and level. People often say compliance, but WCAG itself uses the word conformance. No tool can certify it for a whole site.
What is WCAG accessibility?
WCAG is the set of guidelines the W3C publishes for making web content usable by people with disabilities. It is organized into four principles and many testable criteria, and laws and contracts often refer to it.
What are the WCAG compliance requirements?
The requirements depend on who asks. A law or contract names a version and a level, usually 2.1 or 2.2 Level AA. The criteria themselves are listed in the table above.
What is a WCAG 2.2 AA checklist?
It is the list of Level A and Level AA criteria in WCAG 2.2 turned into checks you can perform, such as contrast, keyboard operation and labels. The W3C publishes the criteria, and the table above explains them in plain language.
Where can I find a WCAG 2.2 checklist template or Excel file?
The W3C's quick reference and WebAIM's checklist are good starting points, and many teams copy them into a spreadsheet with columns for result, evidence, owner and date. Make a template that matches how you test.
Is there a WCAG 2.2 AAA checklist?
Yes, the WCAG 2.2 criteria include Level AAA, which is stricter. The W3C does not recommend requiring AAA for entire sites, since some content cannot meet every AAA criterion. Many teams adopt selected AAA items where they fit.
What is a web content accessibility guidelines audit?
It is an evaluation of a site against WCAG, usually with automated tools and manual checks, written up as findings with pages, criteria and fixes. See accessibility audit cost for what is involved.
Is the WCAG compliance deadline the same for everyone?
No. WCAG has no deadline of its own. Deadlines come from laws such as the Title II rule or from contracts, and each sets its own date.
This guide is general information, not legal advice. Laws and deadlines change; check the linked sources and ask a qualified attorney about your own situation.
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Clir runs automated checks against WCAG 2.2 Level A and AA success criteria. How Clir tests.