WCAG 2.1 Accessibility Standard

WCAG 2.1 was published in June 2018, and extends WCAG 2.0 by adding mobile accessibility plus additional success criteria for people with low vision, cognitive and learning disabilities.

Web Content Accessibility Guidelines 2.1 (WCAG 2.1 - 2018)

Rules

This section lists the 318 rules covering 43 checkpoints for WCAG 2.1 supported by the current version of the product.

1.1 Text Alternatives

1.1.1 A Non-text Content - 22 rules

Applet with no fallback content (HTML)
Image map has no accessible name (HTML)
ARIA image has no accessible name (HTML)
Image has no accessible name (HTML)
alt is image file name (PDF and HTML)
Graphic button has no accessible name (HTML)
Object with no fallback content (HTML)
ASCII art used for text alternative (HTML)
Image accessible name uses placeholder (HTML)
PDF graphic has no accessible name (PDF)
button image must have alt (HTML)
Frame src contains an image instead of HTML (HTML)
Server-side image maps are inaccessible (HTML)
Alt text does not convey color information (HTML)
Object has no accessible name (HTML)
Placeholder for timed media (HTML)
Decorative image missing null alt attribute (HTML)
Spacer image has descriptive alt (HTML)
Decorative image with accessible name (HTML)
SVG has no accessible name (HTML)
Unicode lookalike characters used (HTML)
Word graphic has no accessible name (Office documents)

1.2 Time Based Media

1.2.1 A Audio-only and Video-only (Prerecorded) - 2 rules

Image accessible name uses placeholder (HTML)
Placeholder for timed media (HTML)

1.2.2 A Captions (Prerecorded) - No rules

1.2.3 A Audio Description or Media Alternative (Prerecorded) - No rules

1.2.4 AA Captions (Live) - No rules

1.2.5 AA Audio Description (Prerecorded) - No rules

1.2.6 AAA Sign Language (Prerecorded) - No rules

1.2.7 AAA Extended Audio Description (Prerecorded) - No rules

1.2.8 AAA Media Alternative (Prerecorded) - No rules

1.2.9 AAA Audio-only (Live) - No rules

1.3 Adaptable

1.3.1 A Info and Relationships - 85 rules

Headings should not contain headings (HTML)
Mark up lists and list items properly (HTML)
Data table without th headers (HTML)
Complex header associations need headers attribute (HTML)
Layout table contains data table markup (HTML)
Layout table contains summary or caption (HTML)
fieldset without legend (HTML)
fieldset with invalid legend (HTML)
label is blank (HTML)
PDF not tagged (PDF)
PDF security blocks accessibility (PDF)
Use h1-h6 instead of heading-like styles (HTML)
Use h1-h6 instead of heading-like images (HTML)
Use strong instead of CSS font-weight (HTML)
ARIA table has missing cells (HTML)
HTML table has missing cells (HTML)
Spaces used to simulate table layout (HTML)
JavaScript simulated link (HTML)
fieldset with no form elements (HTML)
CSS content: not available to all users (HTML)
Broken cell headers ID reference (HTML)
Data table hidden by role=presentation (HTML)
Word table without row and column headers (Office documents)
table cannot have ancestor caption (HTML)
main cannot have ancestor a (HTML)
main cannot have ancestor address (HTML)
main cannot have ancestor article (HTML)
main cannot have ancestor aside (HTML)
main cannot have ancestor audio (HTML)
main cannot have ancestor blockquote (HTML)
main cannot have ancestor canvas (HTML)
main cannot have ancestor caption (HTML)
main cannot have ancestor dd (HTML)
main cannot have ancestor del (HTML)
main cannot have ancestor details (HTML)
main cannot have ancestor dialog (HTML)
main cannot have ancestor dt (HTML)
main cannot have ancestor fieldset (HTML)
main cannot have ancestor figure (HTML)
main cannot have ancestor footer (HTML)
main cannot have ancestor header (HTML)
main cannot have ancestor ins (HTML)
main cannot have ancestor li (HTML)
main cannot have ancestor main (HTML)
main cannot have ancestor map (HTML)
main cannot have ancestor nav (HTML)
main cannot have ancestor noscript (HTML)
main cannot have ancestor object (HTML)
main cannot have ancestor section (HTML)
main cannot have ancestor slot (HTML)
main cannot have ancestor td (HTML)
main cannot have ancestor th (HTML)
main cannot have ancestor video (HTML)
role=cell must be owned by role=row (HTML)
role=option must be owned by role=listbox (HTML)
role=menuitem must be owned by role=menu or menubar (HTML)
role=menuitemcheckbox must be owned by role=menu or menubar (HTML)
role=menuitemradio must be owned by role=menu or menubar or group (HTML)
role=tab must be owned by role=tablist (HTML)
role=treeitem must be owned by role=tree or group (HTML)
role=listitem must be owned by role=list (HTML)
role=gridcell must be owned by role=row (HTML)
role=columnheader must be owned by role=row (HTML)
role=rowheader must be owned by role=row (HTML)
role=row must be owned by role=grid or rowgroup or treegrid or table (HTML)
role=rowgroup must be owned by role=grid or treegrid or table (HTML)
`role=feed` must contain `role=article` (HTML)
`role=grid` must contain `role=row` or `rowgroup` (HTML)
`role=list` must contain `role=listitem` (HTML)
`role=listbox` must contain `role=option` (HTML)
`role=menu` must contain `role=menuitem` or `menuitemcheckbox` or `menuitemradio` (HTML)
`role=radiogroup` must contain `role=radio` (HTML)
`role=row` must contain `role=cell` or `columnheader` or `gridcell` or `rowheader` (HTML)
`role=rowgroup` must contain `role=row` (HTML)
`role=table` must contain `role=row` or `rowgroup` (HTML)
`role=tablist` must contain `role=tab` (HTML)
`role=tree` must contain `role=treeitem` (HTML)
`role=treegrid` must contain `role=row` or `rowgroup` (HTML)
Broken aria-activedescendant ID reference (HTML)
Broken aria-owns ID reference (HTML)
Element dd requires dl parent (HTML)
Element dt requires dl parent (HTML)
Element li requires ol or ul parent (HTML)
Element option requires select or optgroup parent (HTML)
Element summary requires details` parent (HTML)

1.3.2 A Meaningful Sequence - 7 rules

Right-to-left language without dir (HTML)
dir=ltr for right-to-left language (HTML)
CSS position: causes meaningless sequence (HTML)
Word has spaces between each letter (HTML)
Spaces used to simulate table layout (HTML)
Table contains a nested table (HTML)
Word graphic not inline (Office documents)

1.3.3 A Sensory Characteristics - 1 rule

Frame title must describe function (HTML)

1.3.4 AA Orientation (new in 2.1) - 1 rule

Screen orientation locked (HTML)

1.3.5 AA Identify Input Purpose (new in 2.1) - 2 rules

Autocomplete value is invalid (HTML)
No autocomplete on password field (HTML)

1.3.6 AAA Identify Purpose (new in 2.1) - No rules

1.4 Distinguishable

1.4.1 A Use of Color - 2 rules

Alt text does not convey color information (HTML)
Links only indicated by color (HTML)

1.4.2 A Audio Control - 2 rules

Autoplay sound longer than 3 seconds (HTML)
Autoplay media longer than 3 seconds (HTML)

1.4.3 AA Contrast (Minimum) - 2 rules

CSS depends on default colors (HTML)
Text contrast below minimum (HTML)

1.4.4 AA Resize Text - 2 rules

CSS absolute units and zoom disabled (HTML)
Zoom disabled by meta viewport (HTML)

1.4.5 AA Images of Text - No rules

1.4.6 AAA Contrast (Enhanced) - 3 rules

1.4.7 AAA Low or No Background Audio - No rules

1.4.8 AAA Visual Presentation - 2 rules

CSS depends on default colors (HTML)
Justified text is hard to read (HTML)

1.4.9 AAA Images of Text (No Exception) - No rules

1.4.10 AA Reflow (new in 2.1) - No rules

1.4.11 AA Non-Text Contrast (new in 2.1) - 1 rule

Control has poor contrast (HTML)

1.4.12 AA Text Spacing (new in 2.1) - 3 rules

CSS line-height cannot be resized (HTML)
CSS letter-spacing cannot be resized (HTML)
CSS word-spacing cannot be resized (HTML)

1.4.13 AA Content on Hover or Focus (new in 2.1) - No rules

2.1 Keyboard Accessible

2.1.1 A Keyboard - 13 rules

iframe with interactive elements is excluded from tab order (HTML)
Scrollable element not keyboard accessible (HTML)
Server-side image maps are inaccessible (HTML)
mouseup handler without keyboard equivalent (HTML)
mouseover handler without keyboard equivalent (HTML)
mouseout handler without keyboard equivalent (HTML)
mousedown handler without keyboard equivalent (HTML)
click handler without keyboard equivalent (HTML)
dblclick handler without keyboard equivalent (HTML)
Keyboard handler without tabindex (HTML)
JavaScript simulated link (HTML)
Field blurs when focused (HTML)
Clickable control with no role (HTML)

2.1.2 A No Keyboard Trap - No rules

2.1.3 AAA Keyboard (No Exception) - 11 rules

Scrollable element not keyboard accessible (HTML)
Server-side image maps are inaccessible (HTML)
mouseup handler without keyboard equivalent (HTML)
mouseover handler without keyboard equivalent (HTML)
mouseout handler without keyboard equivalent (HTML)
mousedown handler without keyboard equivalent (HTML)
click handler without keyboard equivalent (HTML)
dblclick handler without keyboard equivalent (HTML)
Keyboard handler without tabindex (HTML)
JavaScript simulated link (HTML)
Field blurs when focused (HTML)

2.1.4 A Character Key Shortcuts (new in 2.1) - No rules

2.2 Enough Time

2.2.1 A Timing Adjustable - 4 rules

2.2.2 A Pause, Stop, Hide - 7 rules

CSS animation longer than 5 seconds (HTML)
Scrolling marquee element (HTML)
Flashing blink element (HTML)
Animated image longer than 5 seconds (HTML)
Autoplay video longer than 5 seconds (HTML)
CSS causes blinking (HTML)
JavaScript causes blinking (HTML)

2.2.3 AAA No Timing - No rules

2.2.4 AAA Interruptions - 4 rules

2.2.5 AAA Re-authenticating - No rules

2.2.6 AAA Timeouts (new in 2.1) - No rules

2.3 Seizures and Physical Reactions

2.3.1 A Three Flashes or Below Threshold - 1 rule

Don’t use large flashing images (HTML)

2.3.2 AAA Three Flashes - 1 rule

Don’t use any flashing images (HTML)

2.3.3 AAA Animation from Interactions (new in 2.1) - 1 rule

Interaction animation cannot be disabled (HTML)

2.4 Navigable

2.4.1 A Bypass Blocks - 2 rules

Frame title is frame file name (HTML)
Broken skip link (HTML)

2.4.2 A Page Titled - 4 rules

Document title missing (PDF and HTML)
Document title is blank (PDF and HTML)
Document title is placeholder (PDF and HTML)
Document title used on multiple pages (HTML)

2.4.3 A Focus Order - 1 rule

Tab order wrong (HTML)

2.4.4 A Link Purpose (In Context) - 4 rules

Image map has no accessible name (HTML)
HTML link has no accessible name (HTML)
Same link text in same context goes to different pages (HTML)
Ambiguous link text with no context (HTML)

2.4.5 AA Multiple Ways - 1 rule

Provide multiple ways to reach page (HTML)

2.4.6 AA Headings and Labels - 2 rules

label is blank (HTML)
Generic radio button labels need a fieldset (HTML)

2.4.7 AA Focus Visible - 2 rules

Field blurs when focused (HTML)
CSS outline or border hides focus indicator (HTML)

2.4.8 AAA Location - No rules

2.4.9 AAA Link Purpose (Link Only) - 6 rules

Image map has no accessible name (HTML)
HTML link has no accessible name (HTML)
Ambiguous link text (PDF and HTML)
Same link text goes to different pages (HTML)
Same link text in same context goes to different pages (HTML)
Ambiguous link text with no context (HTML)

2.4.10 AAA Section Headings - 1 rule

Page with no headings (PDF and HTML)

2.5 Input Modalities

2.5.1 A Pointer Gestures (new in 2.1) - No rules

2.5.2 A Pointer Cancellation (new in 2.1) - No rules

2.5.3 A Label in Name (new in 2.1) - 1 rule

Visual label not in accessible name (HTML)

2.5.4 A Motion Actuation (new in 2.1) - No rules

2.5.5 AAA Target Size (new in 2.1) - 1 rule

Clickable area smaller than 44 by 44 pixels (HTML)

2.5.6 AAA Concurrent Input Mechanisms (new in 2.1) - No rules

3.1 Readable

3.1.1 A Language of Page - 2 rules

Page lang is invalid (HTML)
Missing page language (PDF and HTML)

3.1.2 AA Language of Parts - 2 rules

Element lang is invalid (HTML)
Language change without lang attribute (HTML)

3.1.3 AAA Unusual Words - No rules

3.1.4 AAA Abbreviations - No rules

3.1.5 AAA Reading Level - 1 rule

Page is hard to read (HTML)

3.1.6 AAA Pronunciation - No rules

3.2 Predictable

3.2.1 A On Focus - 2 rules

Unexpected popup on page load (HTML)
Field blurs when focused (HTML)

3.2.2 A On Input - 3 rules

select change event blocks keyboard navigation (HTML)
Form submits on focus change (HTML)
Script opens new window without warning (HTML)

3.2.3 AA Consistent Navigation - No rules

3.2.4 AA Consistent Identification - No rules

3.2.5 AAA Change on Request - 10 rules

Timed meta tag page refresh (HTML)
Timed meta tag page redirect (HTML)
Link target opens new window without warning (HTML)
JavaScript opens new window without warning (HTML)
Form auto-submits when tabbing (HTML)
Unexpected popup on page load (HTML)
Timed HTTP page refresh (HTML)
Popup appears when control value changes (HTML)
Timed JavaScript page refresh (HTML)
Unexpected JavaScript popup (HTML)

3.3 Input Assistance

3.3.1 A Error Identification - No rules

3.3.2 A Labels or Instructions - 3 rules

fieldset without legend (HTML)
fieldset with invalid legend (HTML)
Grouped fields need a label or instructions (HTML)

3.3.3 AA Error Suggestion - No rules

3.3.4 AA Error Prevention (Legal, Financial, Data) - No rules

3.3.5 AAA Help - No rules

3.3.6 AAA Error Prevention (All) - No rules

4.1 Robust

4.1.1 A Parsing - 1 rule

Parsing (obselete) (HTML)

4.1.2 A Name, Role, Value - 134 rules

4.1.3 AA Status Messages (new in 2.1) - No rules