Fix JavaScript Forced Reflows

How to optimize staging.learn.wowlearnings.org

Next.js SiteScore: 58/100Analyzed May 2026Re-analyze this site

Fix JavaScript Forced Reflows

Medium Impact+8 points estimated

Why It Matters

Forced reflows cause 88ms of unnecessary layout work, blocking user interactions and hurting INP.

How to Fix

Batch DOM reads and writes together in your React components. Use CSS transforms instead of changing layout properties like width/height. Implement useLayoutEffect sparingly and prefer useEffect for non-critical DOM measurements in React.

0Needs Improvement

What This Score Means

A score of 58 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

5.6s
Poor

Good: < 2.5s

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

INP

Interaction to Next Paint

286ms
Needs Improvement

Good: < 200ms

Measures how quickly the page responds to user interactions

CLS

Cumulative Layout Shift

0.01
Good

Good: < 0.1

Measures visual stability - how much content shifts during page load

AI Performance Analysis

This Next.js/React site has poor performance with a score of 58/100, indicating significant user experience issues. The biggest problem is excessive unused JavaScript (281 KiB of wasted code) and render-blocking CSS files that are delaying page rendering by over 500ms, causing your Largest Contentful Paint to suffer at 5.6 seconds. Your site is also loading legacy JavaScript polyfills that modern browsers don't need, wasting an additional 40 KiB, and has forced reflows that are hurting interactivity. Removing unused code, optimizing CSS delivery, and updating your build process to target modern browsers could dramatically improve your Core Web Vitals and boost your performance score by 30+ points.

Other Optimization Recommendations

Remove Unused JavaScript Code

High Impact+15 points estimated

Why It Matters:

Unused JavaScript wastes 281 KiB and delays LCP by 750ms, significantly impacting page load performance.

How to Fix:

Use Next.js tree-shaking by importing only specific functions (import { specific } from 'library'). Remove or defer Google Analytics until after page load using next/script with strategy='afterInteractive'. Run webpack-bundle-analyzer to identify and eliminate unused dependencies in your Next.js build.

Eliminate Render-Blocking CSS Resources

High Impact+12 points estimated

Why It Matters:

Blocking CSS delays initial paint by 510ms and prevents users from seeing content quickly.

How to Fix:

Move critical CSS inline in your Next.js _document.js file using styled-jsx or CSS-in-JS. Use next/dynamic with ssr: false for non-critical components. Split CSS using Next.js automatic code splitting and load non-critical stylesheets asynchronously with media='print' onload="this.media='all'".

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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