How can I optimize my Webflow site to improve my Lighthouse score? Specifically, I need help with converting images to next-gen format, removing unused JavaScript, eliminating render-blocking resources, efficiently encoding images, reducing the number of fonts loading on page load, improving site speed with a global CDN, defining explicit heights and widths for images, and minimizing main thread work. Thank you!

Improving your Lighthouse score in Webflow requires a multi-faceted approach across assets, performance settings, and design techniques.

1. Convert Images to Next-Gen Formats

• Use WebP format for images. Webflow automatically generates WebP versions, but you should manually upload optimized assets when possible.
• Upload compressed images (using tools like TinyPNG or Squoosh) beforehand to ensure minimal size from the start.

2. Remove Unused JavaScript

• Audit your custom code embeds (such as third-party widgets) and remove any unnecessary external scripts.
• Minimize use of heavy libraries like jQuery unless absolutely necessary.
• Use Webflow’s built-in interactions when possible instead of external JavaScript libraries.

3. Eliminate Render-Blocking Resources

• Defer custom JS by wrapping script URLs with defer attributes if added via the Page Settings > Custom Code area.
• Minimize CSS in the page header. Use Webflow’s Page Load interactions to trigger animations after page content loads.

4. Efficiently Encode Images

• Pre-compress images before uploading them into Webflow using image optimization tools.
• Use SVGs wherever possible for icons and simple graphics for faster loading and scalability without quality loss.

5. Reduce Fonts Loading on Page Load

• Use a single font family and limit font weights (e.g., Bold, Regular only).
• Host fonts via Webflow or select system/default fonts when appropriate to avoid extra HTTP requests.
• Audit Font Manager (under the Fonts tab in Webflow Project Settings) to remove unused fonts.

6. Improve Site Speed with a Global CDN

• Publish through Webflow's hosting which already uses a global CDN (fastly and Amazon Cloudfront).
• Enable Asset Minification in Project Settings > Hosting by turning on "Minify HTML," "Minify CSS," and "Minify JavaScript."

7. Define Explicit Heights and Widths for Images

• Always set width and height properties in the Image Settings within the designer or via custom CSS.
• This stabilizes layout shifts and improves your CLS (Cumulative Layout Shift) score drastically.

8. Minimize Main Thread Work

• Reduce complex interactions and page load animations.
• Use smaller, simpler images and limit the number of high-resolution videos and Lottie files.
• Delay non-critical elements such as chats, popups, and animations using load-after-content strategies.

Summary

To optimize your Webflow site for a higher Lighthouse score, convert all images to WebP, remove unused JS, minimize render-blocking resources, efficiently encode assets, limit fonts, take advantage of Webflow’s CDN, set explicit image dimensions, and reduce main thread burdens by simplifying loading tasks. Consistent application of these best practices will lead to major improvements in speed, SEO, and user experience.