Building a website that loads quickly and performs flawlessly requires attention to detail. Lighthouse, Google's performance auditing tool, can help identify issues and suggest solutions. Let’s explore how to achieve a high Lighthouse score while maintaining a balance between technical requirements and user convenience.
Why Minimize Main Screen Layout Shifts?
The main screen is what users see in the first seconds of interaction. To make this experience pleasant, you must avoid unexpected shifts of elements during loading.
Here’s how to achieve it:
- Set fixed width and height attributes for images. This helps the browser reserve space before the media loads.
- Ensure the main screen’s styles load first. Use CSS preloading for critical layout elements.
- Avoid animations at the start. All elements should remain static for faster rendering.
How to Reduce Total Blocking Time (TBT)?
TBT measures the time the browser is busy executing scripts and unresponsive to user interactions. To improve this metric:
- Distribute resource loading effectively. The main screen should only include critical styles and scripts, while other content can load dynamically as users scroll.
- Defer non-essential scripts. Use defer and async to prevent blocking the main thread.
- Run critical operations on-demand. For example, initialize scripts for interactions in other parts of the site only after the user scrolls there.
Effective File Caching
Caching is essential for fast content loading for returning visitors.
- Set a long cache duration. Static resources, such as images and styles, can have a TTL of 6–12 months.
- Use unique file hashes. This ensures content updates don’t conflict with outdated cached files.
Is Resource Minification Necessary?
Minification removes unnecessary elements from files (comments, spaces, etc.), reducing their size and speeding up loading.
- CSS and JS: Minify using tools like Webpack, Terser, or Gulp.
- HTML: Reduce page size with plugins like html-minifier.
Why Lazy-Loading Matters
Lazy-loading delays the loading of content until it’s needed, improving initial load times.
- Images: Use the loading="lazy" attribute for media files outside the main screen.
- Interactive Content: Postpone loading scripts for modules or videos until users interact with them.
Catering to High-Density Screens (Retina)
Modern devices with Retina displays require higher-quality images. To accommodate them:
- Use the <picture> element to provide multiple file versions.
- Provide double-resolution images for devices with high pixel density.
Optimizing SVG Performance
SVG is an excellent format for vector graphics, but it can cause performance issues with complex animations or shadows. In such cases:
- Use PNG or WebP for highly detailed images.
- Optimize SVG files with tools like SVGO.
Conclusion
Optimizing for Google PageSpeed Insights is not just about achieving high scores but also about improving user experience. Every approach described contributes to creating a fast, reliable, and modern website. Remember: every detail matters!
