Optimize JavaScript
without breaking your site
Keep your site interactive and fast with NitroPack’s JavaScript optimization. Remove, delay, and combine scripts—without hassle, risk, or guesswork.
64.4 trillion JavaScript files optimized
Why is JavaScript optimization important?
Block your entire page
If JS files load too early or aren’t optimized, they block rendering—delaying visible content and frustrating users. This also directly harms your First Contentful Paint (FCP) and Largest Contentful Paint (LCP) scores.
Sluggish response times
When scripts take too long to execute, your site becomes laggy, delaying clicks, scrolls, and animations. This leads to poor Interaction to Next Paint (INP) scores, more rage clicks, and higher bounce rates.
Unexpected content shifts
JavaScript often modifies page elements after loading, but if done inefficiently, it can cause content to jump around unexpectedly. This leads to poor Cumulative Layout Shift (CLS) scores, making the page feel unstable.
How NitroPack optimizes your JavaScript files
Remove Render-Blocking Resources
Prevent JS files from blocking your page load, allowing content to render faster for a smoother experience.
Resource Loader Script
Reorders how JavaScript is processed, reducing main thread congestion and improving page rendering speed.
JavaScript Minification
Removes unnecessary characters, comments, and line breaks to reduce file size and improve load speed—without affecting functionality.
Delayed Scripts
Prioritize essential content by loading non-critical scripts after the page has rendered, ensuring faster page loads.
Combine JavaScript
Merge multiple JavaScript files into one to reduce network requests and improve overall performance.
JavaScript Compression
Reduces JavaScript file size by rewriting its binary code and encoding data more efficiently, using fewer bits than the original.
No more JS warnings in your Google PSI report
Minimize main-thread work- Reduce JavaScript execution time
- Eliminate render-blocking resources
- Avoid serving legacy JavaScript to modern browsers
FAQs
What’s the difference between minify, defer, and delay JavaScript?
Minifying reduces JavaScript file size by removing unnecessary characters, comments, and line breaks. Deferring postpones JS execution until after the page has fully loaded. Delaying, on the other hand, holds off loading non-essential scripts until after user interaction, improving the initial page rendering.
Will NitroPack’s JavaScript optimizations break my website?
NitroPack optimizes JavaScript safely, but if visual discrepancies occur, our Performance Engineering team can fine-tune your settings to strike the right balance between speed and stability.
Can I exclude certain JavaScript files from NitroPack’s optimizations?
Yes! NitroPack allows you to exclude specific JavaScript files from optimization manually. This is useful if certain scripts need to load immediately or should remain untouched for compatibility reasons.
Can I revert changes if NitroPack’s JavaScript optimization causes issues?
Yes, you can disable JavaScript optimizations anytime through the NitroPack dashboard. You can also adjust individual settings or exclude problematic scripts to prevent any potential issues from happening.
Does NitroPack optimize JavaScript for mobile differently than for desktop?
Yes! NitroPack applies device-specific optimizations, ensuring JavaScript is optimized differently for mobile and desktop users. This prevents unnecessary scripts from loading on mobile, improving performance while maintaining a smooth user experience across all devices.