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Max Lockwood
Max Lockwood

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How to Center a Div in Flexbox

How to Center a Div in Flexbox

There are many ways to center things in CSS, but CSS Flexbox is one of the simplest. CSS Flexbox is a layout model that aids in the alignment of one-directional items. In this short post, we’ll look at how to center items both horizontally and vertically.

To center the Div element

  • We use the property of display set to flex – display: flex;
  • Align items to center using – align-items: center;
  • The last step is to set justify-content to center – justify-content: center;

Main Axis and Cross Axis

  • All flex boxes have a direction, in this case it’s horizontal starting from the left side to the right
  • The main axis goes from left to right
  • The cross axis is top to bottom

Main Axis and Cross Axis of Flexbox

To center our box we use the align-items property to align our item on the cross axis, which in this case is the block axis running vertically. We use justify-content to align the item on the main axis, which in this case is the inline axis running horizontally.

It is also important to add a height to the container of your div. For example height: 100vh. vh unit stands for viewport height. Specifying 100vh is equivalent to occupying 100% of entire visible screen height.


<div class="box">
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.box {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100vh;

.box div {
  width: 200px;
  height: 200px;
  border: 2px solid #0b2535;
  border-radius: 5px;
  background-color: #e2ecee;
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Centered Div Element


The properties we have covered in this guide are as follows:

  • display: flex – This defines a flex container; inline or block depending on the given value. It enables a flex context for all its direct children.
  • align-items – controls alignment of all items on the cross axis.
  • justify-content – controls alignment of all items on the main axis.

See also
How do you use Cascading Style Sheets (CSS)?
What are the 4 properties in a CSS Box Model?
What are CSS Rules and Selectors?

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Top comments (1)

nickap profile image
nickap • Edited

It's worth mentioning that if we have only one flex-item we want to center, like in the example, we can just use margin:auto in that item, to center on "flex-item level". Of course, then we wouldn't use align-items: center; justify-content: center; in the container because we don't center on "flex-container level"!