Reference
WCAG guidelines in plain English
WCAG, the Web Content Accessibility Guidelines, is the W3C standard for websites that people with disabilities can use. US courts and the Department of Justice point to it for the ADA, and the European standard behind the European Accessibility Act is built on it. This page explains how WCAG is put together, says what each of the 13 guidelines means in plain words, and lists every level A and AA success criterion in WCAG 2.2 with a one-line summary.
How WCAG is built
WCAG has four layers, from broad to specific.
- Principles. There are four, and each is a test the content has to pass. The next section lists them with their guidelines.
- Guidelines. Thirteen goals sit under the principles, such as "provide text alternatives". A guideline is a goal, so you cannot test it directly.
- Success criteria. These are the testable rules under each guideline. A page either meets a criterion or it does not. WCAG 2.2 has 86 of them.
- Levels. Each criterion has a level: A, AA or AAA. Level A is the minimum. AA is the level that laws and contracts usually ask for. AAA is the highest.
The levels stack. To meet level AA, a page meets every A criterion and every AA criterion. That is 55 criteria in WCAG 2.2 and 50 in WCAG 2.1. The W3C does not recommend requiring AAA for a whole site, because some content cannot meet every AAA criterion.
The four principles and 13 guidelines in plain English
- Perceivable: people can see or hear the content.
- 1.1 Text Alternatives: images, icons and image buttons have a text version a screen reader can read out.
- 1.2 Time-based Media: video and audio have captions, transcripts or audio description.
- 1.3 Adaptable: headings, lists, tables and form labels are in the code, so the structure holds when a screen reader reads the page or the layout changes.
- 1.4 Distinguishable: text and controls are easy to see and hear, with enough contrast, zoom that works, and no message given by color alone.
- Operable: people can use it.
- 2.1 Keyboard Accessible: everything works with a keyboard alone.
- 2.2 Enough Time: people get enough time to read and act.
- 2.3 Seizures and Physical Reactions: nothing flashes in a way that can cause a seizure.
- 2.4 Navigable: people can find their way, with page titles, clear links and headings, a way to skip the menu, and visible keyboard focus.
- 2.5 Input Modalities: controls are easy to use with a mouse, a finger or other pointers, with simple taps, targets big enough to hit, and another way to do anything that needs dragging.
- Understandable: people can follow it.
- 3.1 Readable: the language of the page is set, so screen readers pronounce the words correctly.
- 3.2 Predictable: pages behave the way people expect, and menus stay the same from page to page.
- 3.3 Input Assistance: forms help people avoid mistakes and fix them.
- Robust: it works with the browsers and assistive tools people use, such as screen readers.
- 4.1 Compatible: the code tells assistive technology what each control is, what it is called and what state it is in.
WCAG 2.2 quick reference: every level A and AA criterion
The tables list all 55 level A and AA success criteria in WCAG 2.2, grouped by principle. Each name links to the W3C's explanation. Six are marked "new in 2.2". Take those six out, add back 4.1.1 Parsing, which 2.2 removed, and you have the 50 criteria of WCAG 2.1 AA. The 31 AAA criteria are left out here; the full WCAG 2.2 text has them.
Perceivable
| Criterion | Level | What it asks |
|---|---|---|
| 1.1.1 Non-text Content | A | Images, icons and image buttons have a text alternative. Decorative images are hidden from screen readers. |
| 1.2.1 Audio-only and Video-only (Prerecorded) | A | A recorded audio clip has a transcript, and a recorded video with no sound has a text or audio version. |
| 1.2.2 Captions (Prerecorded) | A | Recorded videos with sound have captions. |
| 1.2.3 Audio Description or Media Alternative (Prerecorded) | A | Recorded videos have audio description or a full text version of what they show. |
| 1.2.4 Captions (Live) | AA | Live video with sound has captions. |
| 1.2.5 Audio Description (Prerecorded) | AA | Recorded videos have audio description of what is only shown on screen. |
| 1.3.1 Info and Relationships | A | Headings, lists, tables and form labels are marked up in the code, not only styled to look that way. |
| 1.3.2 Meaningful Sequence | A | The order of the content in the code makes sense when read in sequence. |
| 1.3.3 Sensory Characteristics | A | Instructions do not depend only on shape, size, position or sound, such as "press the round button on the right". |
| 1.3.4 Orientation | AA | The page works whether a phone or tablet is held upright or sideways. |
| 1.3.5 Identify Input Purpose | AA | Fields that ask for personal details, such as name, email or address, say so in the code, so browsers can fill them in. |
| 1.4.1 Use of Color | A | Color is never the only way information is shown, such as a red border as the only sign of an error. |
| 1.4.2 Audio Control | A | Sound that plays by itself for more than 3 seconds can be paused or turned down. |
| 1.4.3 Contrast (Minimum) | AA | Text has a contrast ratio of at least 4.5 to 1 against its background, or 3 to 1 for large text. |
| 1.4.4 Resize Text | AA | Text can be zoomed to 200% without content or functions getting lost. |
| 1.4.5 Images of Text | AA | Text is real text, not a picture of text, except in logos and similar cases. |
| 1.4.10 Reflow | AA | At 400% zoom, or on a screen 320 pixels wide, the page reads without scrolling sideways. Maps and data tables are exceptions. |
| 1.4.11 Non-text Contrast | AA | Buttons, form field borders, focus outlines and icons that carry meaning have a contrast ratio of at least 3 to 1. |
| 1.4.12 Text Spacing | AA | Nothing gets cut off or overlaps when a reader increases line, letter, word and paragraph spacing. |
| 1.4.13 Content on Hover or Focus | AA | Pop-ups that appear on hover or focus can be closed without moving the pointer, can be hovered over, and stay until the reader moves on. |
Operable
| Criterion | Level | What it asks |
|---|---|---|
| 2.1.1 Keyboard | A | Everything on the page can be done with a keyboard alone. |
| 2.1.2 No Keyboard Trap | A | Keyboard focus can always move away from any element. |
| 2.1.4 Character Key Shortcuts | A | Shortcuts that use a single character key, such as a letter or a number, can be turned off or changed, or work only when their element has focus. |
| 2.2.1 Timing Adjustable | A | Time limits can be turned off, changed or extended, with a few exceptions. |
| 2.2.2 Pause, Stop, Hide | A | Content that moves, blinks, scrolls or updates by itself can be paused, stopped or hidden. |
| 2.3.1 Three Flashes or Below Threshold | A | Nothing flashes more than three times in one second, unless the flash is small or dim enough to be safe. |
| 2.4.1 Bypass Blocks | A | There is a way to skip blocks that repeat on every page, such as the main menu. |
| 2.4.2 Page Titled | A | Each page has a title that says what it is. |
| 2.4.3 Focus Order | A | Keyboard focus moves through the page 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 from the text around it. |
| 2.4.5 Multiple Ways | AA | There is more than one way to find a page, such as the menu plus a search or a site map. |
| 2.4.6 Headings and Labels | AA | Headings and labels describe their topic or purpose. |
| 2.4.7 Focus Visible | AA | Keyboard focus is visible. |
| 2.4.11 Focus Not Obscured (Minimum) | AA, new in 2.2 | The element with keyboard focus is not completely hidden behind a sticky header, a cookie banner or other content. |
| 2.5.1 Pointer Gestures | A | Anything that needs a pinch, a swipe or a drawn path also works with a single tap or click. |
| 2.5.2 Pointer Cancellation | A | Actions happen when the pointer is released, not when it is pressed, or they can be stopped or undone. |
| 2.5.3 Label in Name | A | The name a screen reader announces for a control contains the text shown on it. |
| 2.5.4 Motion Actuation | A | Anything done by shaking or tilting the device can also be done another way, and the motion can be turned off. |
| 2.5.7 Dragging Movements | AA, new in 2.2 | Anything done by dragging can also be done with single clicks or taps. |
| 2.5.8 Target Size (Minimum) | AA, new in 2.2 | Click and tap targets are at least 24 by 24 pixels, or have enough space around them. Links inside text are an exception. |
Understandable
| Criterion | Level | What it asks |
|---|---|---|
| 3.1.1 Language of Page | A | The main language of the page is set in the code. |
| 3.1.2 Language of Parts | AA | Passages in another language are marked with their language. |
| 3.2.1 On Focus | A | Moving focus to an element does not change the page by itself, such as submitting a form or opening a new window. |
| 3.2.2 On Input | A | Changing a field or a setting does not change the page by itself, unless the reader was told it would. |
| 3.2.3 Consistent Navigation | AA | Menus and other navigation that repeat across pages stay in the same order. |
| 3.2.4 Consistent Identification | AA | Things that do the same job have the same name on every page. |
| 3.2.6 Consistent Help | A, new in 2.2 | Help that appears on several pages, such as contact details or a chat, sits in the same place relative to the rest of the page. |
| 3.3.1 Error Identification | A | When a form finds an error, it shows which field is wrong and describes the problem in text. |
| 3.3.2 Labels or Instructions | A | Fields that need input have labels or instructions. |
| 3.3.3 Error Suggestion | AA | When a form knows how to fix an error, it tells the reader how. |
| 3.3.4 Error Prevention (Legal, Financial, Data) | AA | Orders, legal agreements and changes to stored data can be undone, are checked for errors, or can be confirmed before they go through. |
| 3.3.7 Redundant Entry | A, new in 2.2 | Information the reader already entered in the same process is filled in again or offered, not asked for twice. |
| 3.3.8 Accessible Authentication (Minimum) | AA, new in 2.2 | Logging in does not require remembering, retyping or solving a puzzle, unless there is another way or help, such as allowing paste and password managers. Recognizing objects in pictures is allowed. |
Robust
| Criterion | Level | What it asks |
|---|---|---|
| 4.1.2 Name, Role, Value | A | Every control tells assistive technology its name, role and state. Standard HTML controls do this already; custom-built ones often do not. |
| 4.1.3 Status Messages | AA | Status messages, such as "added to cart" or "5 results", are announced by screen readers without moving focus. |
What changed from WCAG 2.1 to 2.2
WCAG 2.2 became a W3C standard in October 2023, and the W3C published an updated version in December 2024. The changes are small.
- Nine new criteria. Six are at level A or AA: 2.4.11 Focus Not Obscured (Minimum), 2.5.7 Dragging Movements, 2.5.8 Target Size (Minimum), 3.2.6 Consistent Help, 3.3.7 Redundant Entry and 3.3.8 Accessible Authentication (Minimum). Three are at AAA: 2.4.12 Focus Not Obscured (Enhanced), 2.4.13 Focus Appearance and 3.3.9 Accessible Authentication (Enhanced).
- One criterion is gone. The W3C marked 4.1.1 Parsing as obsolete. It was written for screen readers that read the raw code, and they no longer do. The problems it covered are gone or fall under other criteria.
Everything else is the same. In the W3C's words, "sites which conform to WCAG 2.2 also conform to WCAG 2.1".
Which version to test against
The W3C recommends WCAG 2.2 as the target, even where a law or a contract names an older version. The rules that name a version still say 2.1 AA: the Department of Justice's 2024 rule for state and local government websites, and EN 301 549, the European standard behind the European Accessibility Act. A site that meets 2.2 AA meets 2.1 AA too, so building to 2.2 covers both. Our audits test WCAG 2.1 AA, the version those rules name.
WCAG and the ADA
The ADA dates from 1990 and does not mention websites or WCAG. For businesses open to the public, no federal rule names a technical standard. The Department of Justice's 2022 guidance calls WCAG helpful guidance and says businesses have flexibility in how they comply. In practice, demand letters, lawsuits and settlements point to WCAG 2.1 AA, which is why audits use it. For what that means for your site, see is my website ADA compliant.
WCAG 3 is still a draft
The W3C is writing WCAG 3.0. It is a Working Draft, last published in September 2026, and it will change before it becomes a standard. No law points to it. For now, test against WCAG 2.1 or 2.2.
How to check your site against WCAG
About a third of the A and AA criteria can be decided by a machine with certainty: an image has an alt attribute or it does not, and a contrast ratio clears 4.5 to 1 or it does not. The rest need a person. Is the alt text useful? Does focus move in an order that makes sense? Can the checkout be finished with a keyboard? To check the parts you can test yourself in a browser, use the ADA compliance checklist. The WCAG compliance check guide explains the three depths of testing and what each one costs.
Common questions
How many WCAG guidelines are there?
Thirteen, under four principles. Under the guidelines sit the success criteria: 86 in WCAG 2.2 and 78 in WCAG 2.1. People often say "guidelines" when they mean the criteria.
What is the difference between WCAG 2.1 and 2.2?
WCAG 2.2 adds nine success criteria, six of them at level A or AA, and removes 4.1.1 Parsing. The rest is the same, so a site that meets 2.2 also meets 2.1.
Which WCAG level do I need?
Level AA. It is the level that laws, courts and contracts refer to. Level A alone is too little, and the W3C does not recommend requiring AAA for a whole site.
Is WCAG 3 replacing WCAG 2.2?
Not yet. WCAG 3.0 is a draft and will change before it is final. WCAG 2.1 and 2.2 are the versions to test against today.
Can an automated tool check all of WCAG?
No. A tool can decide about a third of the A and AA criteria with certainty. The rest need a person with a keyboard and a screen reader. A clean scan means the tool found nothing in the part it can check.