How to zoom-in and zoom-out image using JavaScript ?

Difficulty Level : Expert
Last Updated : 20 Sep, 2019

Given an image and the task is to increase and decrease the image size using JavaScript. Use the following property to increase and decrease the image.

Using Width property: It is used to change the new values to resize the width of the element.

Syntax:

object.style.width = "auto|length|%|initial|inherit"

Approach:

Get the selector of the required image using .getElementById(selector).
Store the current width value in the variable using .clientWidth.
Now change the width value to new using .style.width.
It will proportionally increase and decrease the dimension of an image.

Example:

<!DOCTYPE html>
<html>
  
<head>
    <title>
        How to zoom-in and zoom-out
        image using JavaScript ?
    </title>
      
    <script src=
"https://code.jquery.com/jquery-1.12.4.min.js">
    </script>
</head>
  
<body style="text-align:center;">
      
    <h1 style = "color:green;" > 
        GeeksForGeeks 
    </h1> 
      
    <h3>
        JavaScript | Increase and
        Decrease image size
    </h3>
    <hr>
      
    <div class="box">
          
        <img src=
"https://media.geeksforgeeks.org/wp-content/uploads/20190912174307/qwe1.png" 
            id="geeks" GFG="250" alt="Geeksforgeeks">
    </div>
    <hr>
      
    <button type="button" onclick="zoomin()">
        Zoom-In
    </button>
      
    <button type="button" onclick="zoomout()"> 
        Zoom-Out
    </button>
      
    <script type="text/javascript">
        function zoomin() {
            var GFG = document.getElementById("geeks");
            var currWidth = GFG.clientWidth;
            GFG.style.width = (currWidth + 100) + "px";
        }
          
        function zoomout() {
            var GFG = document.getElementById("geeks");
            var currWidth = GFG.clientWidth;
            GFG.style.width = (currWidth - 100) + "px";
        }
    </script>
</body>
  
</html>           

Output:

Before click on button:
After click on Zoom-In Button:
After click on Zoom-Out Button:

Using Height property: It is used to change the new values to resize the height of the element.

Syntax:

object.style.height = "auto|length|%|initial|inherit"

Approach:

Get the selector of the required image using .getElementById(selector).
Store the current height value in the variable using .clientHeight.
Now change the width value to new using .style.height.
It will proportionally increase and decrease the dimension of an image.

Example:

<!DOCTYPE html>
<html>
  
<head>
    <title>
        How to zoom-in and zoom-out
        image using JavaScript ?
    </title>
      
    <script src=
"https://code.jquery.com/jquery-1.12.4.min.js">
    </script>
</head>
  
<body style="text-align:center;">
      
    <h1 style = "color:green;" > 
        GeeksForGeeks 
    </h1> 
      
    <h3>
        JavaScript | Increase and 
        Decrease image size
    </h3>
    <hr>
      
    <div class="box">
        <img src=
"https://media.geeksforgeeks.org/wp-content/uploads/20190912174307/qwe1.png"
                id="geeks" GFG="250" alt="Geeksforgeeks">
    </div>
    <hr>
      
    <button type="button" onclick="zoomin()"> 
        Zoom-In
    </button>
      
    <button type="button" onclick="zoomout()"> 
        Zoom-Out
    </button>
      
    <script type="text/javascript">
        function zoomin() {
            var GFG = document.getElementById("geeks");
            var currHeight = GFG.clientHeight;
                GFG.style.height = (currHeight + 40) + "px";
        }
        function zoomout() {
            var GFG = document.getElementById("geeks");
            var currHeight = GFG.clientHeight;
                GFG.style.height = (currHeight - 40) + "px";
        }
    </script>
</body>
  
</html>