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

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.

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:

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:

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