How does the `float` property work and how do you clear floats?
Jul 16, 2025 am 01:49 AMThe float attribute of CSS was originally designed to achieve the layout effect of text surrounding images, but was later widely used in page layout. float will cause elements to be separated from the document stream and arranged to the left or right, while other content surrounds it; multiple floating elements will be arranged horizontally as space allows, otherwise they will "drop" below. However, floating causes the parent container to collapse highly, which in turn causes release issues, so floating needs to be cleared. Common ways to clear floats include: 1. Add empty elements with clear:both after the floating element; 2. Use clearfix pseudo-element tricks; 3. Use modern layout methods such as Flexbox or Grid to replace float. Which method to choose depends on project structure and browser compatibility requirements.
The float
property in CSS was originally designed to allow text to wrap around images, like in magazine layouts. But over time, it became a go-to tool for layout purposes — even though that wasn't exactly what it was intended for. Understanding how float
works and how to clear it is key to managing layout flow and avoiding unexpected visual issues.

How the float
Property Works
When you apply float: left
or float: right
to an element, it takes that element out of the normal document flow and pushes it to the specified side. Other content, like text or inline elements, will then wrap around it.
For example:

img { float: left; margin: 10px; }
With this, any text next to the image will flow around it on the right and bottom sides. The floating element will keep moving left (or right) until it hits the edge of its container or another floating element.
Some important behaviors:

- Floated elements are block-level by default, even if they're inline or inline-block.
- Multiple floating elements will line up next to each other if there's enough space.
- If not enough space exists, they'll "drop" down below each other.
This behavior can be useful for things like image galleries or multi-column layouts — but it comes with quirks.
Why You Need to Clear Floats
Because floating elements are removed from the normal flow, their parent containers might collapse — meaning they don't expand to contain the floating children. This can cause layout problems like overlapping elements or misaligned sections.
For instance:
<div class="container"> <div class="box" style="float: left;">Box 1</div> <div class="box" style="float: left;">Box 2</div> </div> <p>This text may appear behind the boxes.</p>
In this case, the .container
div might have zero height because both child boxes are floating. And the paragraph below might start right underneath them instead of after.
To fix this, you need to clear the floats.
How to Clear Floats
There are several common ways to clear floats depending on your needs and context:
Using
clear: both
on a new element : Add an empty element (like a<div>
) withclear: both;
after the floating elements.<div style="clear: both;"></div>
Using a clearfix hack : Apply a class to the container that clears internal floats using pseudo-elements.
.clearfix::after { content: ""; display: table; clear: both; }
Then just add
class="clearfix"
to the container.Using modern layout techniques : With Flexbox or Grid, you often don't need floats at all for layout. These newer methods give more control and avoid float-related issues entirely.
Which method you choose depends on the structure of your layout and browser support requirements. For older projects, the clearfix is still widely used. For newer ones, consider switching to Flexbox or Grid when possible.
Clearing floats isn't complicated once you understand why they cause issues in the first place. Whether you use a clearfix, an extra div, or skip floats altogether with modern layout tools, knowing how to manage them give you better control over your page's structure.
Basically that's it.
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