Upgrade JavaScript Build Target Configuration

How to optimize staging.learn.wowlearnings.org

Next.js SiteScore: 52/100Analyzed May 2026Re-analyze this site

Upgrade JavaScript Build Target Configuration

Medium Impact+8 points estimated

Why It Matters

Legacy JavaScript polyfills add 40 KiB of unnecessary code that modern browsers don't need.

How to Fix

Update your Next.js config to target modern browsers by setting target: 'es2020' in next.config.js. Configure Babel to exclude unnecessary polyfills for Array.prototype.at, Object.hasOwn, and other modern features. Use browserslist to define your supported browser versions.

0Needs Improvement

What This Score Means

A score of 52 falls in the "Needs Improvement" range (50-89). While it is better than poor (0-49), you should aim for 90+ to provide an optimal user experience and maximize SEO benefits.

This site is slower than approximately 35% of similar sites. The main issues affecting performance are image optimization, JavaScript execution time, and layout stability.

Addressing these issues could improve your conversion rate by 15-20% and boost your search engine rankings.

Core Web Vitals Analysis

LCP

Largest Contentful Paint

6.2s
Poor

Good: < 2.5s

Measures how long it takes for the main content to appear on screen

INP

Interaction to Next Paint

354ms
Needs Improvement

Good: < 200ms

Measures how quickly the page responds to user interactions

CLS

Cumulative Layout Shift

0.00
Good

Good: < 0.1

Measures visual stability - how much content shifts during page load

AI Performance Analysis

This Next.js site has poor performance with a score of 52/100, indicating significant user experience issues. The biggest problem is an extremely slow Time to Interactive of 11 seconds, primarily caused by excessive JavaScript execution (4+ seconds) from oversized bundles that contain 281 KiB of unused code and outdated polyfills. The site is also suffering from render-blocking CSS files and forced reflows that delay content painting, resulting in a sluggish 6.2-second Largest Contentful Paint. Removing unused JavaScript, updating the build configuration to eliminate unnecessary polyfills, and optimizing CSS delivery could dramatically improve performance and reduce loading times by several seconds.

Other Optimization Recommendations

Eliminate Render Blocking CSS Resources

High Impact+18 points estimated

Why It Matters:

CSS files are blocking initial render and delaying LCP by 600ms, preventing users from seeing content quickly.

How to Fix:

In your Next.js app, move critical CSS inline using next/head for above-the-fold styles. Use dynamic imports for non-critical CSS chunks. Configure next.config.js to enable CSS optimization with experimental.optimizeCss: true.

Remove Unused JavaScript Code Splitting

High Impact+15 points estimated

Why It Matters:

281 KiB of unused JavaScript is increasing bundle size and delaying LCP by 900ms.

How to Fix:

Use Next.js dynamic imports with React.lazy() for components not needed on initial load. Configure webpack-bundle-analyzer to identify unused code. Remove or defer Google Tag Manager and analytics scripts using next/script with strategy='afterInteractive'.

Keep Your Site Fast After Optimization

Once your site is optimized, maintain that speed. Use DeployHQ for zero-downtime, automated deployments—so performance fixes and updates go live safely every time, without breaking your site.

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