1. css
  2. /properties
  3. /border-top-width



border-top-width is a CSS property that sets the width of the top border of an element. The border-top-width property sets the width of the top border of an element.


Setting the top border width to thin:

element {
    border-top-width: thin;

Setting the top border width to medium:

element {
    border-top-width: medium;

Setting the top border width to thick:

element {
    border-top-width: thick;

Setting the top border width to 5px:

element {
    border-top-width: 5px;

Setting the top border width to 2em:

element {
    border-top-width: 2em;

Setting the top border width to initial value:

element {
    border-top-width: initial;

Setting the top border width to inherit:

element {
    border-top-width: inherit;


thinA thin border is drawn.
mediumA medium border is drawn.
thickA thick border is drawn.
<length>A valid length value, such as pixels (px), ems (em), or points (pt)
initialSets the border-top-width property to its default value.
inheritInherits the border-top-width value from its parent element.

Best Practices

  • Use consistent widths: When specifying the border width, try to use consistent widths throughout your CSS. For example, if you use 2px width for one element, use 2px width for all similar elements.
  • Be mindful of accessibility: Keep in mind that some users may have difficulty distinguishing certain border widths, especially if they have visual impairments. Try to use a combination of widths and patterns to create borders that are easy to see and understand.
  • Test your border widths: Make sure to test your border widths on different devices and browsers to ensure that they look the way you expect them to. Some widths may appear differently on different screens.
  • Use CSS variables: If you need to use the same border-top-width on multiple elements, you can use CSS variables to make it easier to update the width in one place.
  • Use the border-top shorthand property: Instead of using the border-top-width property in conjunction with border-top-color and border-top-style, you can use the border-top shorthand property to set all three properties at once. This makes your code more concise and easier to read.
  • Avoid overusing border-width: Overuse of border-width can make a design look cluttered and overwhelming. Use border-width sparingly and only when necessary to enhance the design.
  • Pay attention to the context: Keep in mind the context in which the element is being used, as certain widths may be more appropriate for certain situations.
  • Use browser-specific prefixes: Keep in mind that some older browsers may not fully support the latest CSS specifications, so you may need to include browser-specific prefixes for your CSS properties to ensure that they are displayed correctly.
  • Use border-top-width in combination with other border properties: For example, when creating a button with certain width, you can use border-top-width along with border-top-color and border--top-style to create a complete button style.
  • Be aware of the impact of border-width on layout: Keep in mind that the border-width property can affect the layout of an element, especially when it's used in combination with other layout properties such as width and height.
  • Be mindful of responsive design: Be sure to consider how border widths will look on different screen sizes and make necessary adjustments for different devices.
  • Use relative units: Use relative units such as em or rem rather than absolute units like px when specifying border widths. This allows your borders to scale when the font size is changed.

Browser Compatibility

ChromeFirefoxSafariInternet ExplorerMicrosoft EdgeOpera