CSS max-block-size Property

Last Updated : 9 Jun, 2026

The max-block-size property in CSS specifies the maximum size an element can have along the block direction. In most horizontal writing modes, it behaves similarly to the max-height property.

  • Limits the maximum size of an element along the block axis.
  • Behaves like max-height in horizontal writing modes and adapts to different writing directions.
  • Supports length values, percentages, and keywords for flexible layouts.

Syntax:

max-block-size: length | percentage | auto | none | min-content |
max-content | fit-content | inherit | initial | unset;

Property values

  • length: It sets a fixed value defined in px, cm, pt etc. Negative values are allowed. Its default value is 0px.
  • percentage (%): It is the same as length but the size is set in term of percentage of the window size.
  • auto: It is used when it is desired that the browser determines the block-size.
  • none: It is used when you don't want to limit on the size of the box.
  • max-content: It is used when you preferred max-width on the size of the box.
  • min-content: It is used when you preferred min-width on the size of the box.
  • fit-content: It is used when you preferred exact-width on the size of the box.
  • initial: It is used to set the value of the max-block-size property to its default value.
  • inherit: It is used when it is desired that the element inherits the max-block-size property of its parent as its own.
  • unset: It is used unset the default max-block-size.

Examples of max-block-size property in CSS

Here are some example discussed:

Example 1: Demonstrates the max-block-size property by limiting the maximum block size of an element and hiding content that exceeds the specified size.

html
<!--Driver Code Starts-->
<!DOCTYPE html>
<html>

<head>
    <title>CSS max-block-size Property</title>
<!--Driver Code Ends-->

    <style>
        body {
            background-color: #e6e6e6;
        }

        h1 {
            color: green;
        }

        .container {
            width: 200px;
            height: 30px;
            background-color: aqua;
            text-align: center;
            margin-left: 35px;
            margin-top: 30px;
            position: relative;
        }

        .bar {
            background-color: green;
            height: 20px;
            width: 200px;
            position: absolute;
            top: 10px;
            left: 0;
        }

        .text {
            position: relative;
            z-index: 1;
            font-size: 18px;
            line-height: 20px;
        }

        .bottom-text {
            text-align: center;
            width: 200px;
            margin-left: 35px;
            font-size: 18px;
        }
    </style>

<!--Driver Code Starts-->
</head>

<body>
    <h1>GeeksforGeeks</h1>

    <h2>CSS | max-block-size Property</h2>

    <div class="container">
        <div class="bar"></div>
        <div class="text">A Computer Science</div>
    </div>

    <div class="bottom-text">Portal for Geeks</div>

</body>

</html>
<!--Driver Code Ends-->

Example 2: Use of the max-block-size property to limit the maximum block size of an element while allowing its content to wrap within the specified size.

html
<!--Driver Code Starts-->
<!DOCTYPE html>
<html>

<head>
    <title>CSS max-block-size Property</title>
<!--Driver Code Ends-->

    <style>
        body {
            background-color: #e6e6e6;
        }

        h1 {
            color: green;
        }

        div {
            background-color: aqua;
            max-block-size: 40px;
            width: 200px;
            overflow: hidden;
            text-align: center;
            font-size: 18px;
            line-height: 20px;
            margin-left: 35px;
        }
    </style>

<!--Driver Code Starts-->
</head>

<body>
    <h1>GeeksforGeeks</h1>

    <h2>CSS | max-block-size Property</h2>

    <div>
        A Computer Science<br>
        Portal for Geeks
    </div>

</body>

</html>
<!--Driver Code Ends-->
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