How to optimize the access speed of PHP website through lazy loading of images?

How to optimize the access speed of PHP website through lazy loading of images?

With the development of mobile Internet, more and more users use mobile devices to access websites. However, due to the relatively slow network speeds of mobile devices, loading speed becomes even more important. Among them, the loading speed of images has a great impact on website performance. In order to improve the access speed of PHP website, you can optimize it by lazy loading of images.

Lazy loading of images means that when the web page is loaded, only the images in the visible area are loaded instead of loading all images at once. In this way, the loading time of the first screen will be greatly shortened, thereby improving the access speed of the website. The following will introduce how to optimize the access speed of PHP websites through lazy loading of images, and provide corresponding code examples.

First of all, we need to introduce the relevant JavaScript library into the PHP file to implement the lazy loading function of images. A commonly used library is LazyLoad, which can be imported through CDN. Add the following code in the

tag of HTML:

<script src="https://cdn.jsdelivr.net/npm/vanilla-lazyload@12.0.0/dist/lazyload.min.js"></script>

Next, we need to add the corresponding attributes to the images on the web page that need to be lazy loaded. Store the image placeholder in the src attribute of the tag, and then store the actual image link in the data-src attribute. The code example is as follows:

<img src="/static/imghwm/default1.png"  data-src="占位符图片链接"  class="lazy" data- alt="图片描述">

Then, we need to initialize the LazyLoad library in JavaScript and pass in the images that need to be lazy loaded. The code example is as follows:

<script>
  var lazyLoad = new LazyLoad({
    elements_selector: "img[data-src]"
  });
</script>

Finally, we need to trigger the lazy loading of images at the right time. A common way is to place JavaScript code at the bottom of the web page to ensure that lazy loading is performed after the web page is loaded. The code example is as follows:

<script>
  window.addEventListener("load", function() {
    lazyLoad.update();
  });
</script>

Through the above steps, we successfully implemented the lazy loading function of images. When a user visits the website, only the images in the visible area will be loaded, which improves the loading speed of the web page.

In addition to the LazyLoad library, there are also some other image lazy loading libraries, such as Lozad.js and Echo.js. You can choose a suitable library according to specific needs for lazy loading of images.

To sum up, lazy loading of images can optimize the access speed of PHP websites. By loading only images within the visible area, the time required for first loading can be reduced and the user experience improved. I hope this article will help you understand the optimization method of lazy loading of images.

Reference link:

1. [LazyLoad GitHub repository](https://github.com/verlok/lazyload)
2. [Lozad.js](https: //github.com/ApoorvSaxena/lozad.js)
3. [Echo.js](https://github.com/toddmotto/echo)

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