How to get image size (height & width) using JavaScript?

Question

Are there any JavaScript or jQuery APIs or methods to get the dimensions of an image on the page?

Answer 1

ok guys, i think i improved the source code to be able to let the image load before trying to find out its properties, otherwise it will display '0 * 0', because the next statement would have been called before the file was loaded into the browser. Requires jquery...

function getImgSize(imgSrc){
    var newImg = new Image();
    newImg.src = imgSrc;
    var height = newImg.height;
    var width = newImg.width;
    p = $(newImg).ready(function(){
        return {width: newImg.width, height: newImg.height};
    });
    alert (p[0]['width']+" "+p[0]['height']);
}

Answer 2

You can only really do this using a callback of the load event as the size of the image is not known until it has actually finished loading. Something like the code below...

var imgTesting = new Image();

function CreateDelegate(contextObject, delegateMethod)
{
    return function()
    {
        return delegateMethod.apply(contextObject, arguments);
    }
}

function imgTesting_onload()
{
    alert(this.width + " by " + this.height);
}


imgTesting.onload = CreateDelegate(imgTesting, imgTesting_onload);
imgTesting.src = 'yourimage.jpg';

Answer 3

Before using real image size you should load source image. If you use JQuery framework you can get real image size in simple way.

$("ImageID").load(function(){
  console.log($(this).width() + "x" + $(this).height())
})

Answer 4

If you are using jQuery and you are requesting image sizes you have to wait until they load or you will only get zeroes.

$(document).ready(function() {
    $("img").load(function() {
        alert($(this).height());
        alert($(this).width());
    });
});

Answer 5

I think an update to these answers is useful because one of the best-voted replies suggests using clientWidth and clientHeight, which I think is now obsolete.

I have done some experiments with HTML5, to see which values actually get returned.

First of all, I used a program called Dash to get an overview of the image API. It states that height and width are the rendered height/width of the image and that naturalHeight and naturalWidth are the intrinsic height/width of the image (and are HTML5 only).

I used an image of a beautiful butterfly, from a file with height 300 and width 400. And this Javascript:

var img = document.getElementById("img1");

console.log(img.height,           img.width);
console.log(img.naturalHeight,    img.naturalWidth);
console.log($("#img1").height(),  $("#img1").width());

Then I used this HTML, with inline CSS for the height and width.

<img style="height:120px;width:150px;" id="img1" src="img/Butterfly.jpg" />

Results:

/*Image Element*/ height == 300         width == 400
           naturalHeight == 300  naturalWidth == 400
/*Jquery*/      height() == 120       width() == 150

/*Actual Rendered size*/    120                  150

I then changed the HTML to the following:

<img height="90" width="115" id="img1" src="img/Butterfly.jpg" />

i.e. using height and width attributes rather than inline styles

Results:

/*Image Element*/ height ==  90         width == 115
           naturalHeight == 300  naturalWidth == 400
/*Jquery*/      height() ==  90       width() == 115

/*Actual Rendered size*/     90                  115

I then changed the HTML to the following:

<img height="90" width="115" style="height:120px;width:150px;" id="img1" src="img/Butterfly.jpg" />

i.e. using both attributes and CSS, to see which takes precedence.

Results:

/*Image Element*/ height ==  90         width == 115
           naturalHeight == 300  naturalWidth == 400
/*Jquery*/      height() == 120       width() == 150

/*Actual Rendered size*/    120                  150

Answer 6

You can apply the onload handler property when the page loads in js or jquery like this:-

$(document).ready(function(){
   var width = img.clientWidth;
   var height = img.clientHeight;

 });