WCAG in Plain English

The purpose of regions and common elements must be defined in the code using semantic HTML or ARIA attributes, so that; assistive technologies can communicate their meaning, and; browsers can adapt or simplify the interface (e.g. hide non-essential content).

Color must not be the only way to convey information. Always provide an additional visual cue, like icon, text label, underline, shape, or pattern (e.g. striped, solid).

Text contrast against its background must be at least 4.5:1 for normal text, or 3:1 for large text (over 24px, or bold and over 19px).

Text remains readable and usable when zoomed to 200%.

Text must be actual text, not images of text, unless a specific visual presentation is absolutely necessary (e.g. logo).

Text contrast against its background must be at least 7:1 for normal text, or 4.5:1 for large text (over 24px, or bold and over 19px).

Blocks of text (like paragraphs) must have a line height of at least 1.5, not be justified, and stay within 80 characters (or 40 for CJK scripts). Allow users to adjust spacing and colors using custom styles.

Text must be actual text, not images of text (no exception, not even for design or aesthetic reasons).

Content remains functional and easy to read when; zoomed to 400% or; viewed at 320px width, without needing to scroll in two directions (except for tables, maps, and similar content).

Interactive controls (e.g. buttons, form fields, focus indicators) and graphics that convey meaning (e.g. icons, charts, graph lines) must have a contrast ratio of at least 3:1 against adjacent colors.