Key tips for optimizing website performance

What are the techniques for website performance optimization? Specific code examples are required

With the development of the Internet, websites have become a way for people to obtain information, communicate and achieve business goals. important tool. However, with the increase in the number of website users and the expansion of functions, website performance problems have become increasingly prominent. A website with low performance not only affects user experience, but may also lead to user loss and transaction failure. Therefore, website performance optimization has become an important issue that developers must face.

For website performance optimization, developers can adopt some techniques and strategies to improve the website’s response speed and loading performance. Here are some common optimization tips, with specific code examples:

1. Image Optimization:
   Images often take up the majority of a website’s bandwidth and load time. In order to optimize the image loading speed, you can take the following measures:

   • Compress images: Use image compression algorithms to reduce the size of image files, thereby speeding up image loading. For example, you can use an image editing tool or an online compression service to compress pictures.

   <img src="image.jpg" alt="示例图片"   style="max-width:90%">

2. Use CDN acceleration:
   CDN (content distribution network) can distribute the static resources of the website to servers around the world, and users can download them from the nearest server resources to speed up web page loading. The sample code using CDN acceleration is as follows:

   <script src="https://cdn.example.com/jquery.min.js"></script>

3. Merge and compress CSS and JavaScript files:
   Merge multiple CSS and JavaScript files into one file and use the compression algorithm to reduce Small file size. This reduces HTTP request and transfer times and improves website loading speed.

   The sample code is as follows:

   <link rel="stylesheet" type="text/css" href="styles.css">
   <script src="script.js"></script>

4. Use caching:
   Using the caching mechanism can reduce requests to the server, thereby speeding up the response speed of the website. You can specify the expiration time of static resources by setting cache header information.

   The sample code is as follows:

   <?php
   $expiry = 60 * 60 * 24 * 7; // 缓存过期时间为7天
   header("Cache-Control: public, max-age=$expiry");
   ?>

5. Lazy loading:
   Lazy loading technology can load images and other resources when the user scrolls the page, thereby improving the initial page Loading speed.

   The sample code is as follows:

   <img src="placeholder.jpg" data-src="image.jpg" alt="示例图片"   style="max-width:90%">
   <script>
   document.addEventListener("DOMContentLoaded", function() {
       var images = document.querySelectorAll("img[data-src");
       images.forEach(function(img) {
           img.src = img.getAttribute("data-src");
       });
   });
   </script>

The above are just some common website performance optimization techniques and specific code examples. In fact, website performance optimization is a complex and meticulous process that needs to be adjusted and optimized according to specific circumstances. Developers should fully understand the website's architecture and performance bottlenecks, and take appropriate optimization measures based on actual conditions to improve website performance and user experience.

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