Design Nomenclature / Systems & Spec
Text spacing
Also called SC 1.4.12, text spacing override, text spacing bookmarklet
This entry has not been translated yet and is shown in English.
WCAG 2.1 SC 1.4.12, Level AA: no content or functionality is lost when the reader overrides line height to 1.5× the font size, spacing after paragraphs to 2×, letter spacing to 0.12×, and word spacing to 0.16×. It tests whether containers give, not whether the defaults were well chosen.
In practice
Read as a recommendation to set those values. It isn't — it is a stress test, and what it catches is fixed-height boxes and text clipped by its own container.
Not to be confused with
- TrackingA uniform adjustment to the space after every glyph in a run — CSS letter-spacing. Size-dependent: display type usually wants negative tracking because the sidebearings were fitted for text, while small caps, all-caps runs and small labels want positive. Body text at text size almost never wants any.
- LeadingThe vertical distance from one baseline to the next. It is set against measure, not in isolation: a long line needs more of it for the eye to find the next line's start, a short line needs less. Under-leaded text merges lines; over-leaded text dissolves the paragraph into stripes.