max-height

The max-height CSS property sets the maximum height of an element. It prevents the used value of the height property from becoming larger than the value specified for max-height.

max-height overrides height, but min-height overrides max-height.

Syntax

/* <length> value */
max-height: 3.5em;

/* <percentage> value */
max-height: 75%;

/* Keyword values */
max-height: none;
max-height: max-content;
max-height: min-content;
max-height: fit-content(20em);

/* Global values */
max-height: inherit;
max-height: initial;
max-height: unset;

Values

<length>

Defines the max-height as an absolute value.

<percentage>

Defines the max-height as a percentage of the containing block's height.

none

No limit on the size of the box.

max-content

The intrinsic preferred max-height.

min-content

The intrinsic minimum max-height.

fit-content(<length-percentage>)

Uses the fit-content formula with the available space replaced by the specified argument, i.e. min(max-content, max(min-content, argument)).

Accessibility concerns

Ensure that elements set with a max-height are not truncated and/or do not obscure other content when the page is zoomed to increase text size.

• MDN Understanding WCAG, Guideline 1.4 explanations
• Understanding Success Criterion 1.4.4 | W3C Understanding WCAG 2.0

Formal definition

Formal syntax

auto | <length> | <percentage> | min-content | max-content | fit-content(<length-percentage>)
where 
<length-percentage> = <length> | <percentage>

Examples

Setting max-height using percentage and keyword values

table { max-height: 75%; }

form { max-height: none; }

Specifications

Browser compatibility

See also

• The box model, box-sizing
• height, min-height