Does "Display:None" Prevent an Image from Loading

Does display:none prevent an image from loading?

Browsers are getting smarter. Today your browser (depending on the version) might skip the image loading if it can determine it's not useful.

The image has a display:none style but its size may be read by the script.
Chrome v68.0 does not load images if the parent is hidden.

You may check it there : http://jsfiddle.net/tnk3j08s/

You could also have checked it by looking at the "network" tab of your browser's developer tools.

Note that if the browser is on a small CPU computer, not having to render the image (and layout the page) will make the whole rendering operation faster but I doubt this is something that really makes sense today.

If you want to prevent the image from loading you may simply not add the IMG element to your document (or set the IMG src attribute to "data:" or "about:blank").

Why does `display: none` not load background image?

So I found this interesting because I didn't know about that. To conclude the image won't load if the item or one of its parents settings is display: none. Is it because browsers get smarter? I don't think so. I tried the following:

#test1 {
    display: none;
}

<div id="test1">
   <img src="http://www.dumpaday.com/wp-content/uploads/2017/01/random-pictures-116.jpg"/>
</div>

Prevent images from loading

If you render the HTML on the page, even if it's hidden, it's going to load. If you want images to load only when they're needed, you're going to have to dynamically set the source (src) on the image tag in javascript.

Edit 1: The script you referenced merely checks to see how far you've scrolled the page down and then determines which images are visible (or almost visible) by checking their top -- see the $.belowthefold and $.rightoffold extensions.

The example works great when the images are all the same size because their containers can also be the same size and you won't get any odd page resizing behavior when you lazy load them. If your images' heights and widths vary, you may get some odd results.

Edit 2:

<script type="text/javascript" charset="utf-8">
    $(document).ready( function() { $("img").removeAttr("src"); } );
</script>

<img src="Chrysanthemum.jpg" />
<img src="Desert.jpg" />
<img src="Hydrangeas.jpg" />
<img src="Jellyfish.jpg" />
<img src="Koala.jpg" />
<img src="Lighthouse.jpg" />
<img src="Penguins.jpg" />
<img src="Tulips.jpg" />

Does display:none keep elements from loading?

Would this work?

Nope. display: none will only prevent the element from being displayed; it will be loaded nevertheless.

You can watch this happen in the element inspector of your choice (e.g. in Firebug or IE8's dev tools).

The best way is probably to create the Video element using JavaScript afterwards, or - if you want a fail-safe solution in case JS is turned off - you could use an iframe that loads the video if the user clicks a link.

Don't load hidden images

Here's a jQuery solution:

$(function () {
   $("img").not(":visible").each(function () {
       $(this).data("src", this.src);
       this.src = "";
   });

   var reveal = function (selector) {
       var img = $(selector);
       img[0].src = img.data("src");
   }
});

It's similar to your solution, except it doesn't use the fakeSrc attribute in the markup. It clears the src attribute to stop it from loading and stores it elsewhere. Once you are ready to show the image, you use the reveal function much like you do in your solution. I apologize if you do not use jQuery, but the process should be transferable to whichever framework (if any) that you use.

Note: This code specifically must be ran before the window has fired the load event but after the DOM has been loaded.

Does "Display:None" Prevent an Image from Loading