CSS tab-size Property

The tab-size property is used to set the width of the tab character (U+0009) displaying on the page.

The tab-size property is one of the CSS3 properties. It is only visible for <textarea> and <pre> HTML tags.

Negative values are invalid.
For maximum browser compatibility -moz- for Firefox and -o- for Opera extensions are used with this property.
Initial Value 8
Applies to Block containers.
Inherited Yes.
Animatable No.
Version CSS3
DOM Syntax object.style.tabSize = "20";


tab-size: number | length | initial | inherit;

Example of the tab-size property:

<!DOCTYPE html>
    <title>Title of the document</title>
      .tab1 {
        -moz-tab-size: 5; /* Firefox */
        -o-tab-size: 5;/* Opera 10.6-12.1 */
        tab-size: 5;
      .tab2 {
        -moz-tab-size: 20;/* Firefox */
        -o-tab-size: 20;/* Opera 10.6-12.1 */
        tab-size: 20;
    <h2>Tab-size property example</h2>
    <pre class="tab1">
        Lorem	ipsum	is	a...  
    <pre class="tab2">
        Lorem	ipsum	is	a...


CSS tab-size values list

In the given example, the tab-size of the first element is 5, the one of the second element is 20.


Value Description Play it
number Sets the number of the space characters in the tab. Negative values are invalid. The default value is 8. Play it »
length Sets the width of the tab. Negative values are invalid. This value is not supported by major browsers.
initial Makes the property use its default value. Play it »
inherit Inherits the property from its parent element.

Browser support

chrome edge firefox safari opera
42.0+ 53.0 -webkit- 29.0+

Practice Your Knowledge

What does the 'tab-size' property in CSS do?

Quiz Time: Test Your Skills!

Ready to challenge what you've learned? Dive into our interactive quizzes for a deeper understanding and a fun way to reinforce your knowledge.

Do you find this helpful?