What is a cache policy and how to set the right HTTP cache policy to serve your static files.
Delay loading images that appear below-the-fold for faster rendering of above-the-fold page content.
Asynchronously load non-critical CSS files with loadCSS to avoid blocking page rendering.
How to use 'font-display' descriptor for a website that uses Google Fonts.
How to lazy load images for faster load times with no negative SEO impact.
Make sure that images hidden through 'display:none' are not downloaded by the browser.
How to reliably serve WebP images without browser compatibility or legacy image format issues.
Load small background images on smaller screens and large ones on larger screens.