What can I do to improve the JavaScript performance of my Webflow site?

To improve JavaScript performance on your Webflow site, you should optimize both custom scripts and third-party integrations for speed and efficiency.

1. Audit Existing JavaScript Usage

• Review custom code added in the Webflow Designer or Project Settings (inside the Page Settings or Custom Code tabs).
• Identify unused or redundant scripts, especially from third-party widgets or tracking tools.
• Use browser developer tools (like Chrome DevTools) to audit script execution times.

2. Defer or Minimize Third-Party Scripts

• Avoid loading scripts unnecessarily on every page—only load them where they're needed.
• Use the defer or async attributes where possible (e.g., when pasting scripts in the Custom Code section).
• Remove unused library calls (e.g., jQuery, if not used).

3. Optimize Webflow Interactions and Animations

• Minimize the number of complex animations that run on page load or scroll.
• Avoid nesting multiple Webflow interactions that trigger simultaneously.
• Use the “Will-change” CSS property sparingly on highly animated elements, only where necessary.

4. Minimize Custom JavaScript Complexity

• Write efficient code: Avoid heavy DOM manipulations or deeply nested event listeners.
• Use event delegation instead of attaching listeners to many individual elements.
• Limit the use of setInterval, setTimeout, or continuous polling.

5. Reduce Render-Blocking Scripts

• Move custom JavaScript to the footer (Before tag) from the header where possible.
• Use Webflow’s page-level Custom Code feature to restrict JS to only relevant pages.

6. Optimize Timing of Script Execution

• Delay non-critical JS execution using:
• Page Load triggers
• Intersection Observer API (for scroll-based lazy loading or firing functions only when needed)
• Use Webflow’s built-in interactions first, before resorting to JavaScript for basic animations.

7. Lazy Load External Resources

• If you're dynamically loading content (like with Ajax), load scripts after user interaction or visibility.
• Lazy load assets like YouTube embeds or maps using loading="lazy" or toggle visibility based on user actions.

Summary

To boost JavaScript performance on your Webflow site, limit unnecessary scripts, defer execution when possible, and optimize animations and event handling. Combine Webflow’s native features with efficient, minimal JavaScript to ensure fast and smooth performance.