Images
All <img> elements include ALT attribute
Images used for decoration include empty ALT text (alt="") and no title attribute
CSS background images are not used to convey important information or provide functionality, such as navigation or branding
Keyboard Operability
All functionality is keyboard operable (including interactive User Interface components)
The keyboard tab order follows logical page order
Where mouse event handlers are used, keyboard handlers are also available
Change of page context should be controllable by user
When an element receives keyboard focus, there is a visual indicator such as an outline
No keyboard traps exist (i.e., the keyboard user can navigate in and out of page elements)
Reading Order
Content reading order is linear and logical in the absence of styles and formatting
Forms
Forms are fully keyboard-operable
All form fields are associated with <label> elements
All error prevention and handling are exposed to and navigable by all users
Document structure
Pages begin with a top-level heading, marked up as <h1>
Pages use appropriate landmarks, particularly the "main" role.
Pages maintain a hierarchical heading structure, skipping no heading levels
Pages should include a unique <title>
<Title> should be meaningful and relevant to the page contents
Page and section layout are achieved by using semantic elements such as <body>, <div>, <section>, <article> etc.
Magnification
Page maintains legibility after page magnification in browser
Content maintains legibility after text magnification
Links
Ensure that links are focusable and can be activated by keyboard
Use unique text to identify hyperlinks (e.g., "More about Diversity"; "Proceed to Checkout")
Link text uses device-neutral wording, such as "Proceed to…"
Links are visually identifiable, and distinguishable from other page content
Multimedia
Video is accompanied by a synchronized caption and audio by a transcript
All video should be presented with an available closed-caption
All media should be presented in a keyboard-operable player
Tables
Tables use <th> and <td> to present data
Table headers and table data cells are related by SCOPE, ID/HEADERS or other associative markup
Color and Styles
Foreground and background contrast must be sufficient (=>4.5:1 for regular text)
Font sizes should be defined as percentages, ems, or by named sizes
User Interface Components and Widgets
Interactive elements are enhanced progressively, built on elements with native functionality such as links and buttons
Custom UI components have appropriate role, state, and accessible text labels
