Jquery magnifier of an image

Written by @kerixa 23 February 2014

By this tool, you have a nice magnifier on your page and user can zoom on specific part of image and like magnifier of windows, see the details of the image.

Code Snippet:

                                                
                                                <!-- this script is provided by https://www.htmlbestcodes.com coded by: Kerixa Inc. -->

<html>
<head>
<style type="text/css">
/*Some CSS*/
* {margin: 0; padding: 0;}
.magnify {width: 200px; margin: 50px auto; position: relative;}

/*Lets create the magnifying glass*/
.large {
	width: 175px; height: 175px;
	position: absolute;
	border-radius: 100%;
	
	/*Multiple box shadows to achieve the glass effect*/
	box-shadow: 0 0 0 7px rgba(255, 255, 255, 0.85), 
	0 0 7px 7px rgba(0, 0, 0, 0.25), 
	inset 0 0 40px 2px rgba(0, 0, 0, 0.25);
	
	/*Lets load up the large image first*/
	background: url('http://htmlbestcodes.com/files/iphone.jpg') no-repeat;
	
	/*hide the glass by default*/
	display: none;
}

/*To solve overlap bug at the edges during magnification*/
.small { display: block; }
</style>
</head>
<body>
<div class="magnify">
	
	<!-- This is the magnifying glass which will contain the original/large version -->
	<div class="large"></div>
	
	<!-- This is the small image -->
	<img class="small" src="http://htmlbestcodes.com/files/iphone.jpg" width="200"/>
	
</div>

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
<script type="text/javascript">
$(document).ready(function(){

	var native_width = 0;
	var native_height = 0;

	//Now the mousemove function
	$(".magnify").mousemove(function(e){
		//When the user hovers on the image, the script will first calculate
		//the native dimensions if they don't exist. Only after the native dimensions
		//are available, the script will show the zoomed version.
		if(!native_width && !native_height)
		{
			//This will create a new image object with the same image as that in .small
			//We cannot directly get the dimensions from .small because of the 
			//width specified to 200px in the html. To get the actual dimensions we have
			//created this image object.
			var image_object = new Image();
			image_object.src = $(".small").attr("src");
			
			//This code is wrapped in the .load function which is important.
			//width and height of the object would return 0 if accessed before 
			//the image gets loaded.
			native_width = image_object.width;
			native_height = image_object.height;
		}
		else
		{
			//x/y coordinates of the mouse
			//This is the position of .magnify with respect to the document.
			var magnify_offset = $(this).offset();
			//We will deduct the positions of .magnify from the mouse positions with
			//respect to the document to get the mouse positions with respect to the 
			//container(.magnify)
			var mx = e.pageX - magnify_offset.left;
			var my = e.pageY - magnify_offset.top;
			
			//Finally the code to fade out the glass if the mouse is outside the container
			if(mx < $(this).width() && my < $(this).height() && mx > 0 && my > 0)
			{
				$(".large").fadeIn(100);
			}
			else
			{
				$(".large").fadeOut(100);
			}
			if($(".large").is(":visible"))
			{
				//The background position of .large will be changed according to the position
				//of the mouse over the .small image. So we will get the ratio of the pixel
				//under the mouse pointer with respect to the image and use that to position the 
				//large image inside the magnifying glass
				var rx = Math.round(mx/$(".small").width()*native_width - $(".large").width()/2)*-1;
				var ry = Math.round(my/$(".small").height()*native_height - $(".large").height()/2)*-1;
				var bgp = rx + "px " + ry + "px";
				
				//Time to move the magnifying glass with the mouse
				var px = mx - $(".large").width()/2;
				var py = my - $(".large").height()/2;
				//Now the glass moves with the mouse
				//The logic is to deduct half of the glass's width and height from the 
				//mouse coordinates to place it with its center at the mouse coordinates
				
				//If you hover on the image now, you should see the magnifying glass in action
				$(".large").css({left: px, top: py, backgroundPosition: bgp});
			}
		}
	})
});
</script>

</body>
</html><a target='_blank' href='https://www.htmlbestcodes.com' style='font-size: 8pt; text-decoration: none'>Html Best Codes</a>

Example:

About @kerixa

I am Krishna Eydat. I studied Software Engineering at University of Waterloo in Canada. I lead a few tech companies. I am passionate about the way we are connected. I would like to be part of something big or be the big deal!

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