How to set the opacity of background image in CSS ?

Last Updated : 06 Mar, 2024

Setting the opacity of a background image in CSS involves using the background-image property along with the opacity property. By adjusting the opacity, you control the transparency of the background image, allowing elements behind it to partially show through, creating a visually layered effect.

We are using the following approaches to setting the opacity of the background image in CSS:

Table of Content

Using Opacity Property
Using Pseudo-elements

1. Using Opacity Property

The Opacity Property in CSS sets the transparency level of an element and its contents. Accepting values between 0 (fully transparent) and 1 (fully opaque), affects the entire element, including its children, making it a simple and effective way to control transparency in web design.

Syntax:

div {
  opacity: 0.5;
}

Example: The opacity property in the CSS style of the “.element” class is set to 0.3, making the background image semi-transparent. This adjusts the visibility of the background while maintaining text readability.

HTML

<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        <title>Opacity of Background Image</title>
        <style>
            .element {
            width: 300px;
            height: 200px;
            background-image: url(
'https://media.geeksforgeeks.org/wp-content/uploads/20210313130410/exbg.png');
            opacity: 0.3; /* Adjust opacity level */
            color: white;
            text-align: center;
            line-height: 200px;
            }
        </style>
    </head>
    <body>
        <h2 style="color: green;"> GeeksForGeeks</h2>
        <div class="element">
            Background Image with Opacity
        </div>
    </body>
</html>

Output:

Using Opacity Property

2. Using Pseudo-elements:

To set the opacity of a background image in CSS using pseudo-elements, you can apply the opacity property directly to the pseudo-element’s background image, controlling its transparency independently from the element’s content.

Syntax:

selector::pseudo-element {
     property: value;
}

Example: In this example the background image’s opacity is set using the ::before pseudo-element. Adjust the opacity level as needed. Ensure text visibility by positioning it above the pseudo-element using the z-index property.

HTML

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport"
          content="width=device-width, 
                   initial-scale=1.0">
    <title>Opacity of Background Image</title>
    <style>
        .element {
            position: relative;
            width: 300px;
            height: 200px;
            color: white;
            text-align: center;
            line-height: 200px;
            z-index: 1; 
        }
         
        .element::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background-image: url(
'https://media.geeksforgeeks.org/wp-content/uploads/20210313130410/exbg.png');
            opacity: 0.3; /* Adjust opacity level */
            z-index: -1; /* Ensure background image is behind the text */
        }
    </style>
</head>
<body>
    <h2 style="color: green;"> GeeksForGeeks</h2>
    <div class="element">
        Background Image with Opacity
    </div>
</body>
</html>