tab-size

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since August 2021.

The tab-size CSS property is used to customize the width of tab characters (U+0009).

Try it

tab-size: 10px;

tab-size: 16px;

tab-size: 24px;

tab-size: 4;

#example-element {
  border: 1px solid;
}

Syntax

css

/*  values */
tab-size: 4;
tab-size: 0;

/*  values */
tab-size: 10px;
tab-size: 2em;

/* Global values */
tab-size: inherit;
tab-size: initial;
tab-size: revert;
tab-size: revert-layer;
tab-size: unset;

Values

: A multiple of the advance width of the space character (U+0020) to be used as the width of tabs. Must be non-negative. The advance width means the distance a cursor or a print head moves before printing the next character.
: The width of tabs. Must be non-negative.

Formal definition

Initial value	`8`
Applies to	block containers
Inherited	yes
Computed value	the specified integer or an absolute length
Animation type	a length

Formal syntax

tab-size = 
    |

Examples

Expanding by character count

css

pre {
  tab-size: 4; /* Set tab size to 4 characters wide */
}

Collapse tabs

css

pre {
  tab-size: 0; /* Remove indentation */
}

Default tab size vs custom sizes

This example compares a default tab size with a custom tab size. Note that white-space is set to pre to prevent the tabs from collapsing.

HTML

html

no tab
	default tab size of 8 characters wide
	custom tab size of 3 characters wide
   3 spaces, equivalent to the custom tab size
	custom tab size of 50px wide

CSS

body {
  border: 1px solid red;
  margin: 1rem;
}

css

p {
  white-space: pre;
}

.custom-number {
  tab-size: 3;
}

.custom-length {
  tab-size: 50px;
}

Result

Specifications

Specification
CSS Text Module Level 3 # tab-size-property