What are the differences between flex-basis and width in Flexbox ?

Last Updated : 05 Jun, 2020

This article describes the difference between the flex-basis and width property along with examples of usage. The flex-basis property defines the initial size of flex-items depending upon the flex-direction value. It has the following additional properties that can change its behaviour:

The flex-direction value can be set to row or column. If its value is row, it defines the width and if its value is column, it defines the height.
The flex-basis property can be applied only to flex-items and width property can be applied to all.
When using flex property, all the three properties of flex-items i.e, flex-row, flex-shrink and flex-basis can be combined into one declaration, but using width, doing the same thing would require multiple lines of code.
If flex-direction value is set to be column, then for sizing flex-items horizontally width property is used.

The below examples show the differences between flex-basis and the width and height property:

Example 1: Using flex-basis when flex-direction is set to row.

HTML

<!DOCTYPE html>
<html>
  
<head>
    <title>FlexBox</title>
    <style>
        body {
            background: #eee;
        }
  
        h1 {
            color: green;
        }
  
        .wrapper {
            width: 100%;
            margin: 0 auto;
        }
  
        .flex-container {
            display: flex;
            background: #fff;
            flex-wrap: wrap;
            flex-direction: row;
        }
  
        .box {
            /*
      Since flex-direction is set to
      row therefore flex-basis defines 
      the width. Either of the width
      property or flex-basis property
      can be used as both perform
      a similar task in this case.
      */
  
            height: 100px;
            flex-basis: 600px;
        }
  
        .one {
            background: red;
        }
  
        .two {
            background: blue;
        }
  
        .three {
            background: green;
        }
    </style>
</head>
  
<body>
    <h1>GeeksForGeeks</h1>
    <h2>Flex-basis vs Width </h2>
    <br>
    <div class="wrapper">
        <div class="flex-container">
            <div class="box one"></div>
            <div class="box two"></div>
            <div class="box three"></div>
        </div>
    </div>
</body>
  
</html>

Output:

Example 2: Using flex-basis when flex-direction is set to column.

HTML

<!DOCTYPE html>
<html>
  
<head>
    <title>FlexBox</title>
    <style>
        body {
            background: #eee;
        }
  
        h1 {
            color: green;
        }
  
        .wrapper {
            width: 100%;
            margin: 0 auto;
        }
  
        .flex-container {
            display: flex;
            background: #fff;
            flex-wrap: wrap;
            flex-direction: column;
        }
  
        .box {
            /* 
      Since flex-direction is set to
      column therefore flex-basis defines 
      the height and hence overrides the
      height property. The height of
      flex-item will therefore be 80px.
      The width property has to be separately
      assigned a horizontal width.
      */
  
            height: 100px;
            width: 100px;
            flex-basis: 80px;
        }
  
        .one {
            background: red;
        }
  
        .two {
            background: blue;
        }
  
        .three {
            background: green;
        }
    </style>
</head>
  
<body>
    <h1>GeeksForGeeks</h1>
    <h2>Flex-basis vs Width </h2>
    <br>
    <div class="wrapper">
        <div class="flex-container">
            <div class="box one"></div>
            <div class="box two"></div>
            <div class="box three"></div>
        </div>
    </div>
</body>
  
</html>