What methods of ‘clearfix’ can I use?

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I have the age-old problem of a div wrapping a two-column layout. My sidebar is floated, so my container div fails to wrap the content and sidebar.

<div id="container">
  <div id="content"></div>
  <div id="sidebar"></div>
</div>

There seem to be numerous methods of fixing the clear bug in Firefox:

  • <br clear="all"/>
  • overflow:auto
  • overflow:hidden

In my situation, the only one that seems to work correctly is the <br clear="all"/> solution, which is a little bit scruffy. overflow:auto gives me nasty scrollbars, and overflow:hidden must surely have side effects. Also, IE7 apparently shouldn't suffer from this problem due to its incorrect behaviour, but in my situation it's suffering the same as Firefox.

Which method currently available to us is the most robust?

29 Answers

What problems are we trying to solve?

There are two important considerations when floating stuff:

  1. Containing descendant floats. This means that the element in question makes itself tall enough to wrap all floating descendants. (They don't hang outside.)

    Floating content hanging outside its container

  2. Insulating descendants from outside floats. This means that descendants inside of an element should be able to use clear: both and have it not interact with floats outside the element.

    <code>clear: both</code> interacting with a float elsewhere in the DOM

Block formatting contexts

There's only one way to do both of these. And that is to establish a new block formatting context. Elements that establish a block formatting context are an insulated rectangle in which floats interact with each other. A block formatting context will always be tall enough to visually wrap its floating descendants, and no floats outside of a block formatting context may interact with elements inside. This two-way insulation is exactly what you want. In IE, this same concept is called hasLayout, which can be set via zoom: 1.

There are several ways to establish a block formatting context, but the solution I recommend is display: inline-block with width: 100%. (Of course, there are the usual caveats with using width: 100%, so use box-sizing: border-box or put padding, margin, and border on a different element.)

The most robust solution

Probably the most common application of floats is the two-column layout. (Can be extended to three columns.)

First the markup structure.

<div class="container">
  <div class="sidebar">
    sidebar<br/>sidebar<br/>sidebar
  </div>
  <div class="main">
    <div class="main-content">
      main content
      <span style="clear: both">
        main content that uses <code>clear: both</code>
      </span>
    </div>
  </div>
</div>

And now the CSS.

/* Should contain all floated and non-floated content, so it needs to
 * establish a new block formatting context without using overflow: hidden.
 */
.container {
  display: inline-block;
  width: 100%;
  zoom: 1; /* new block formatting context via hasLayout for IE 6/7 */
}

/* Fixed-width floated sidebar. */
.sidebar {
  float: left;
  width: 160px;
}

/* Needs to make space for the sidebar. */
.main {
  margin-left: 160px;
}

/* Establishes a new block formatting context to insulate descendants from
 * the floating sidebar. */
.main-content {
  display: inline-block;
  width: 100%;
  zoom: 1; /* new block formatting context via hasLayout for IE 6/7 */
}

Try it yourself

Go to JS Bin to play around with the code and see how this solution is built from the ground up.

Traditional clearfix methods considered harmful

The problem with the traditional clearfix solutions is that they use two different rendering concepts to achieve the same goal for IE and everyone else. In IE they use hasLayout to establish a new block formatting context, but for everyone else they use generated boxes (:after) with clear: both, which does not establish a new block formatting context. This means things won't behave the same in all situations. For an explanation of why this is bad, see Everything you Know about Clearfix is Wrong.

The overflow property can be used to clear floats with no additional mark-up:

.container { overflow: hidden; }

This works for all browsers except IE6, where all you need to do is enable hasLayout (zoom being my preferred method):

.container { zoom: 1; }

http://www.quirksmode.org/css/clearing.html

I've found a bug in the official CLEARFIX-Method: The DOT doesn't have a font-size. And if you set the height = 0 and the first Element in your DOM-Tree has the class "clearfix" you'll allways have a margin at the bottom of the page of 12px :)

You have to fix it like this:

/* float clearing for everyone else */
.clearfix:after{
  clear: both;
  content: ".";
  display: block;
  height: 0;
  visibility: hidden;
  font-size: 0;
}

It's now part of the YAML-Layout ... Just take a look at it - it's very interesting! http://www.yaml.de/en/home.html

Have you tried this:

<div style="clear:both;"/>

I haven't had any problems with this method.

It is so simple clearfix clears the issue by when we using the float properties inside the div element.If we use two div elements one as float:left; and other one as float:right; we can use clearfix for the parent of the two div element. If we refuse to use clearfix unnecessary spaces fill with contents below and site structure will be broken.

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