The key optimization mode to improve website speed, every front-end developer must master!

Must-have for front-end developers: Master these optimization modes to make your website fly!

With the rapid development of the Internet, websites have become one of the important channels for corporate promotion and communication. A well-performing, fast-loading website not only improves user experience, but also attracts more visitors. As a front-end developer, it is essential to master some optimization patterns. This article will introduce some commonly used front-end optimization techniques to help developers better optimize their websites.

1. Compressed files
   In website development, commonly used file types include HTML, CSS and JavaScript. These files take up a lot of bandwidth and load time during transfer. For these files, you can use compression tools to compress them to reduce the file size and thereby increase loading speed. Compression tools can be implemented through online tools or automated build tools.
2. Picture Optimization
   Pictures are a part of the website that takes up a lot of bandwidth. Optimizing images can reduce their size and increase loading speed. Common optimization methods include using appropriate image formats, reducing image size, using image compression tools, etc.
3. File Cache
   When the browser loads a web page, it will cache part of the content locally. The next time you visit the same web page, you can load it directly from the cache. Developers can tell the browser whether a file needs to be cached and the cache time by setting the cache control parameters in the response header. Reasonable use of file caching can reduce network transmission time and improve web page loading speed.
4. Accelerate using CDN
   CDN (Content Delivery Network) is a technology that speeds up website loading by caching data on a server close to the user. Using CDN, the static resources of the website, such as images, CSS and JavaScript, can be distributed to servers around the world. No matter where users visit the website, they can load these resources from servers closer to them, thus improving the loading speed.
5. Asynchronous loading of resources
   Some resources in the web page, such as JavaScript files, can be loaded asynchronously to improve the loading speed of the page. Put these resources at the bottom of the page, or use defer and async attributes to achieve asynchronous loading. In this way, when the page is loaded, other content of the page can be loaded first to improve the user experience, and then the resource file can be loaded after other content of the page is loaded.
6. Responsive Design
   With the popularity of mobile devices, more and more users access websites through mobile phones and tablets. Developers should use responsive design, which automatically adjusts the layout and style of web pages based on the device's screen size and resolution. This can provide a better user experience and adapt to access from different devices.
7. Reduce HTTP requests
   Every file in the web page needs to be loaded through an HTTP request, and each request takes a certain amount of time. So reducing HTTP requests can effectively reduce web page loading time. Developers can reduce the number of requests by merging CSS and JavaScript files, using sprite images, etc.
8. Use lazy loading
   Lazy loading is a lazy loading technology, that is, the content of this part is loaded only when the user scrolls to the visible area. This can reduce the initial loading time of the page and improve the user experience. Developers can use lazy loading plug-ins to implement lazy loading functionality.
9. Reduce reflow and repaint
   When the DOM structure of the web page changes, the browser will trigger reflow and repaint operations. These operations consume time and computing resources. Developers can avoid frequent changes to the DOM structure, use CSS3 animations instead of JavaScript animations, and rationally use CSS properties to reduce reflow and redraw operations.
10. Reasonable use of JavaScript
    JavaScript is a commonly used scripting language in front-end development, but too much JavaScript code will cause the web page to take longer to load. Developers should use JavaScript rationally, avoid using too many libraries and plug-ins, and place scripts as late as possible to reduce blocking of web page loading.

To sum up, optimizing the front-end performance of the website is a key step in loading pages quickly. Front-end developers need to master some optimization skills, such as compressing files, image optimization, file caching, using CDN acceleration, asynchronous loading of resources, responsive design, reducing HTTP requests, using lazy loading, reducing reflow and redrawing, reasonable use of JavaScript, etc. . Through these optimization modes, front-end developers can make the website fly, improve user experience, and attract more visitors.

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