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POResizing <img> causing slowness
 

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  1. POResizing <img> causing slowness
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    <p>I am working on a site that will have a lot of images inside of boxes (divs) sorted as a grid (absolute positioning). I have noticed that resizing the images to fit the boxes causes the site to slow down significantly. There are a lot of images (342), but I don't understand why this is the case as the site runs quickly when I don't resize them.</p> <p>Please note: I plan on implementing the dynamic resizing of the boxes in the future. <strong>I mention this to avoid the answer of saving every image at another size. I am interested in knowing the cause of the slowdown not a different method of implementation.</strong></p> <p>The grid is initially made up of boxes (divs) that are 150px * 150px. The grid is in the <code>&lt;body&gt;</code> and initially has no images (just empty divs). When the body has loaded, a JavaScript function places the images into their appropriate box. The JavaScript function relies on PHP for getting the images from a database as well as for resizing. Here are the steps for that section of PHP:</p> <p>1.) PHP gets image filename from database.</p> <p>2.) PHP gets image dimensions (in pixels) and saves them into two variables. I'll call them x and y here.</p> <p>3.) I change x and y so that the image will fit 150px * 150px (or whatever initial value I assign to the boxes' initial dimensions).</p> <p>4.) I use <code>echo</code> to <code>write document.getElementById("PHP given Id").innerHTML = '&lt;img src="PHP given filename" style="width:PHP x value; height:PHP y value"/&gt;';</code>.</p> <p>If I comment out step 3 in my code the site runs quickly (that is commenting out the part that changes x and y from the image default dimensions). I have also tried setting the width and height attributes of the <code>&lt;img&gt;</code> instead of inline CSS but that does not solve the slowness issue.</p>
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    1. COModifying width / height will just resize the image manipulation on `DOM`. However, it wouldn't speed up your image things because all of your image is loading on `onload` and after that, you resize it. Try, image thumbnails or `php scripts` that dynamically modify the sizesz.
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      1. POResizing <img> causing slowness
      1. USHamza Waqas
    2. COWell, the browser has to resize those images. If there is 342, it can take some time, more significantly on a slower machine and an older browser.
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      1. USkapa
    3. COWhy are you resizing the images with JS? Why not do it at the same time you generate the HTML?
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