How to center an element in the middle of the browser window?

Viewed 166530

How can I place some HTML element (say, a <div>, for example) in the middle of a browser window (not page, not screen)? Not depending on browser window size, screen resolution, toolbar layout, etc. E.g. I want it to be in the middle of the browser window.

18 Answers

To do this you need to know the size of the element you are centering. Any measurement will do (i.e. px, em, percent), but it has to have a fixed size.

The css will look as follows:

 // Replace X and Y with a number and u with a unit. do calculations
 // and remove parens
.centered_div {
   width: Xu;
   height: Yu;
   position: absolute;
   top: 50%;
   left: 50%;
   margin-left: -(X/2)u;
   margin-top: -(Y/2)u;
}

Edit: This centers in the viewport. You can only center in the browser window using JavaScript. But that might be good enough anyway, since you probably want to display a popup/modal box?

This should work with any div or screen size:

.center-screen {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  min-height: 100vh;
}
 <html>
 <head>
 </head>
 <body>
 <div class="center-screen">
 I'm in the center
 </div>
 </body>
 </html>

See more details about flex here. This should work on most of the browsers, see compatibility matrix here.

I surprised that nobody said about position=fixed. It makes exactly what I asked and works in all "human" browsers and IE since 7.

This is completely possible with just CSS-- no JavaScript needed: Here's an example

Here is the source code behind that example:

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>  
<meta http-equiv="content-type" content="text/html;charset=ISO-8859-1">
<title>Dead Centre</title>  
<style type="text/css" media="screen"><!--
body 
    {
    color: white;
    background-color: #003;
    margin: 0px
    }

#horizon        
    {
    color: white;
    background-color: transparent;
    text-align: center;
    position: absolute;
    top: 50%;
    left: 0px;
    width: 100%;
    height: 1px;
    overflow: visible;
    visibility: visible;
    display: block
    }

#content    
    {
    font-family: Verdana, Geneva, Arial, sans-serif;
    background-color: transparent;
    margin-left: -125px;
    position: absolute;
    top: -35px;
    left: 50%;
    width: 250px;
    height: 70px;
    visibility: visible
    }

.bodytext 
    {
    font-size: 14px
    }

.headline 
    {
    font-weight: bold;
    font-size: 24px
    }

#footer 
    {
    font-size: 11px;
    font-family: Verdana, Geneva, Arial, sans-serif;
    text-align: center;
    position: absolute;
    bottom: 0px;
    left: 0px;
    width: 100%;
    height: 20px;
    visibility: visible;
    display: block
    }

a:link, a:visited 
    {
    color: #06f;
    text-decoration: none
    }

a:hover 
    {
    color: red;
    text-decoration: none
    }

--></style>
</head>
<body>
<div id="horizon">
    <div id="content">
        <div class="bodytext">
        This text is<br>
        <span class="headline">DEAD CENTRE</span><br>
        and stays there!</div>
    </div>
</div>
<div id="footer">
    <a href="http://www.wpdfd.com/editorial/thebox/deadcentre4.html">view construction</a></div>
</body>
</html>
<div align="center">

or

<div style="margin: 0 auto;">

To centre align a div you should apply the style

div 
{
    margin: 0 auto;
}

This is checked and works in all browsers.

<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8">

        <style type="text/css">
            html, body { margin: 0; padding: 0; height: 100%; }

            #outer {height: 100%; overflow: hidden; position: relative; width: 100%;}
            #outer[id] {display: table; position: static;}

            #middle {position: absolute; top: 50%; width: 100%; text-align: center;}
            #middle[id] {display: table-cell; vertical-align: middle; position: static;}

            #inner {position: relative; top: -50%; text-align: left;}
            #inner {margin-left: auto; margin-right: auto;}
            #inner {width: 300px; } /* this width should be the width of the box you want centered */
        </style>
    </head>
    <body>

        <div id="outer">
            <div id="middle">
                <div id="inner">
                    centered
                </div>
            </div>
        </div>

    </body>
</html>

I don't think you can do that. You can be in the middle of the document, however you don't know the toolbar layout or the size of the browser controls. Thus you can center in the document, but not in the middle of the browser window.

If I understand you correct, you want to center the element vertically and horizontally based on the window, not the document. It can be a bit of a pain, but you can use javascript to detect the window size, scroll position, element size, etc. and then position the element in the center of the window (not the document, but the viewable window).

If you want this element to remain in the moddule of the window as you scroll you would need to capture the scroll event and adjust the position.

The code for doing this differs from one browser to the next.

You could write a JavaScript wto find the window height and width and make it to half to find the centre point.

Add you stuff inside a tag, and set the div top and left from the javascript to the centre coordinates you have found using Javascript.

Let me know if you need the code.

Hope this helps. Trick is to use absolute positioning and configure the top and left columns. Of course "dead center" will depend on the size of the object/div you are embedding, so you will need to do some work. For a login window I used the following - it also has some safety with max-width and max-height that may actually be of use to you in your example. Configure the values below to your requirement.

div#wrapper {
    border: 0;
    width: 65%;
    text-align: left;
    position: absolute;
    top:  20%;
    left: 18%;
    height: 50%;
    min-width: 600px;
    max-width: 800px;
}

It works for me :).

div.parent {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100vh;
}
Related