html5 Site Icon CSS3 Site Icon CSS Site Icon

CSS 1/2 Reference

CSS border-left-width property


The CSS border-left-width property allows us to specify the left border width for an element.

Applies To

All elements.

Property Values

CSS allows specification of a border width.

negative values are NOT acceptable when using borders.

border-width - Defines a width for the border.

Valid values for border-width keywords are thin, medium and thick.

A border width can also be expressed in a unit measurement such as em or pixel.

inherit - The border-left-width properties are inherited from the parent element.

Default Value

If a border width is not specified the border width is set to medium, or 0 if the border style property is set to hidden or none.


The border-left-width property is NOT inherited from the parent element unless specified using the inherit property value.

Browser Anomalies

IE5, IE6 and IE7 do not support the inherit property value.
IE8 does with a valid !DOCTYPE.
IE9+ supports the inherit property value.

The interpretation of the width of the border for the thin, medium and thick keywords varies depending on the user agent. The following rules must be true though:

  • Thick must be wider than medium and thin
  • Thin must be narrower than medium or thick
  • Widths must be consistent throughout a document

Position In The Box Model



<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"  
<!-- Our HTML/CSS for the CSS border-left-width property follows -->
<html  xmlns="">
<title>CSS 1/2 Reference - CSS border-left-width Property</title>

<!-- Valid values for CSS border-left-width Property are:
	inherit, thin, medium, thick or a length in a unit 
	measurement such as em or pixel. 

<style type="text/css">

/* Set a border and padding around images to see the 
   effects of changing the right border width */
img {
	padding: 10px;
	border: 2px solid orange;

/* This left border width set to thin */
#img1 {
	border-left-width: thin;

/* This left border width set to medium */
#img2 {
	border-left-width: medium;

/* This left border width set to thick */
#img3 {
	border-left-width: thick;


<h1>Looking at the CSS border-left-width Property</h1>
<p>The next image has a left border width set to thin.
<img id="img1" src=""
    alt="Beef and Ale Pie" />
<p>The next image has a left border width set to medium.
<img id="img2" src=""
    alt="Beef and Ale Pie" />
<p>The next image has a left border width set to thick.
<img id="img3" src=""
    alt="Beef and Ale Pie" />

How It Looks

The results of using the border-left-width property with the values above will look something like the following:

CSS border-left-style    << Prev          Next >>   CSS border-right

go to home page Homepage go to top of page Top

CSS properties

The complete set of visual CSS properties from the latest 2.1 Specification.

Click the links for more information on individual properties and their values.