Web Content Accessibility Guidelines

WCAG 2.1 78 success criteria · W3C Recommendation

WCAG 2.1 kept all of 2.0 and added 17 success criteria, for people with low vision, cognitive and learning disabilities, and people using phones and other pointers. W3C published it on 5 June 2018 and has republished it three times with corrections, most recently on 6 May 2025. It added one guideline: 2.5 Input Modalities.

Level A: 30
Level AA: 20
Level AAA: 28
Published: 5 June 2018

Every criterion All versions WCAG 2.1 at W3C

New in 2.1

Seventeen new success criteria

Most of them help people using phones and touch, people with low vision, and people with cognitive and learning disabilities. They brought a new guideline, 2.5 Input Modalities.

Every criterion

All 78 success criteria in WCAG 2.1

Search, or filter by level and principle. Each one links to its page with a live demo and code examples.

1. Perceivable

Information and interface must be presentable in ways people can perceive.

29 criteria

A 9AA 11AAA 9

1.1

Text Alternatives

1 criterion

1.1.1Level A Non-text Content

1.2

Time-based Media

9 criteria

1.3

Adaptable

6 criteria

1.4

Distinguishable

13 criteria

2. Operable

Interface components and navigation must be operable.

29 criteria

A 14AA 3AAA 12

2.1

Keyboard Accessible

4 criteria

2.2

Enough Time

6 criteria

2.3

Seizures and Physical Reactions

3 criteria

2.4

Navigable

10 criteria

2.5

Input Modalities

6 criteria

3. Understandable

Information and the operation of the interface must be understandable.

17 criteria

A 5AA 5AAA 7

3.1

Readable

6 criteria

3.2

Predictable

5 criteria

3.3

Input Assistance

6 criteria

4. Robust

Content must be robust enough to work with current and future user agents, including assistive technology.

3 criteria

A 2AA 1AAA 0

4.1

Compatible

3 criteria

In WCAG 2.0
New in 2.1
New in 2.2
Removed in 2.2

Guideline	Level A30	Level AA20	Level AAA28
1 Perceivable
1.1 Text Alternatives	1.1.1Non-text Content	—	—
1.2 Time-based Media	1.2.1Audio-only and Video-only (Prerecorded) 1.2.2Captions (Prerecorded) 1.2.3Audio Description or Media Alternative (Prerecorded)	1.2.4Captions (Live) 1.2.5Audio Description (Prerecorded)	1.2.6Sign Language (Prerecorded) 1.2.7Extended Audio Description (Prerecorded) 1.2.8Media Alternative (Prerecorded) 1.2.9Audio-only (Live)
1.3 Adaptable	1.3.1Info and Relationships 1.3.2Meaningful Sequence 1.3.3Sensory Characteristics	1.3.4Orientation 1.3.5Identify Input Purpose	1.3.6Identify Purpose
1.4 Distinguishable	1.4.1Use of Color 1.4.2Audio Control	1.4.3Contrast (Minimum) 1.4.4Resize Text 1.4.5Images of Text 1.4.10Reflow 1.4.11Non-text Contrast 1.4.12Text Spacing 1.4.13Content on Hover or Focus	1.4.6Contrast (Enhanced) 1.4.7Low or No Background Audio 1.4.8Visual Presentation 1.4.9Images of Text (No Exception)
2 Operable
2.1 Keyboard Accessible	2.1.1Keyboard 2.1.2No Keyboard Trap 2.1.4Character Key Shortcuts	—	2.1.3Keyboard (No Exception)
2.2 Enough Time	2.2.1Timing Adjustable 2.2.2Pause, Stop, Hide	—	2.2.3No Timing 2.2.4Interruptions 2.2.5Re-authenticating 2.2.6Timeouts
2.3 Seizures and Physical Reactions	2.3.1Three Flashes or Below Threshold	—	2.3.2Three Flashes 2.3.3Animation from Interactions
2.4 Navigable	2.4.1Bypass Blocks 2.4.2Page Titled 2.4.3Focus Order 2.4.4Link Purpose (In Context)	2.4.5Multiple Ways 2.4.6Headings and Labels 2.4.7Focus Visible	2.4.8Location 2.4.9Link Purpose (Link Only) 2.4.10Section Headings
2.5 Input Modalities	2.5.1Pointer Gestures 2.5.2Pointer Cancellation 2.5.3Label in Name 2.5.4Motion Actuation	—	2.5.5Target Size (Enhanced) 2.5.6Concurrent Input Mechanisms
3 Understandable
3.1 Readable	3.1.1Language of Page	3.1.2Language of Parts	3.1.3Unusual Words 3.1.4Abbreviations 3.1.5Reading Level 3.1.6Pronunciation
3.2 Predictable	3.2.1On Focus 3.2.2On Input	3.2.3Consistent Navigation 3.2.4Consistent Identification	3.2.5Change on Request
3.3 Input Assistance	3.3.1Error Identification 3.3.2Labels or Instructions	3.3.3Error Suggestion 3.3.4Error Prevention (Legal, Financial, Data)	3.3.5Help 3.3.6Error Prevention (All)
4 Robust
4.1 Compatible	4.1.1Parsing 4.1.2Name, Role, Value	4.1.3Status Messages	—

Conformance

What conformance means

A page conforms at a level when it meets every criterion at that level and below, and these five requirements hold.

WCAG 2.1 and 2.2 add that each responsive layout of a page counts as part of the page.

Level
Every criterion at the chosen level and the levels below it is met, or a conforming alternate version is offered.
Full pages
Conformance covers whole pages: a page cannot conform while leaving a part of it out.
Complete processes
When a page is one step of a process, such as a checkout, every step conforms.
Accessibility-supported ways only
The ways content meets the criteria must work with assistive technology and browsers people use.
Non-interference
Anything that is not accessibility-supported must not block the rest of the page; 1.4.2, 2.1.2, 2.2.2 and 2.3.1 apply to everything on it.

Editions

Editions and standards

Content that meets WCAG 2.1 also meets 2.0. Content that meets 2.2 meets 2.1, apart from 4.1.1 Parsing, which 2.2 removed.

Read WCAG 2.1 at W3C

Editions: 5 June 2018, 21 September 2023, 12 December 2024 and 6 May 2025.
Since the September 2023 edition, 4.1.1 Parsing carries a note: treat it as always satisfied for HTML and XML.
EN 301 549 V3.2.1, the European standard of 2021, incorporates WCAG 2.1.