Website display speed is a very important factor that is directly connected to user abandonment rate and SEO. However, when it comes to performance optimization, the common wisdom of the past that ``just do it this way’’ may actually have the opposite effect in modern browser environments.
Here, we’ll debunk common performance improvement myths and explore true best practices.
Myth 1: “All images should be lazy loaded”
It’s easy to misunderstand that if your images are heavy, adding loading="lazy" will make them all faster. While it is certainly effective for off-screen images, it is a big mistake to apply Lazy Load to images that are in first view (the first area you see when you open a page). The browser postpones this, resulting in significantly worse LCP (Largest Contentful Paint). The correct answer is to load first-view images with priority (consider fetchpriority=“high”`).
Misconception 2: “Just minify CSS and JS and you’re done.”
Compressing your code is of course necessary, but it’s not enough. The problem is, ``Are you loading code that you’re not currently using?’’ In a modern approach, “Code Splitting” is important, which splits and loads only the necessary CSS/JS for each screen. Simply stripping out unnecessary third-party scripts (such as unused chat tools and tracking tags) can often lead to dramatic improvements.
Myth 3: “A Google Lighthouse score of 100 is perfect.”
Lighthouse’s score is a great indicator, but it is just a simulation result for your PC and network environment. Real users might be accessing it from old smartphones or unreliable subway lines. The true purpose of Core Web Vitals is “measuring the actual user experience” called RUM (Real User Monitoring). Rather than just relying on your Lighthouse score, it’s important to regularly check the actual field data using something like Google Search Console.
Importance of continuous monitoring
Performance optimization is not a “set it and forget it” task. As you add more features, your site will become a little heavier. The ultimate best practice is to incorporate performance testing into the CI/CD pipeline and create a “system to prevent deterioration” that detects a drop in score when creating a PR.
Let’s update old knowledge and provide a truly comfortable web experience for users.