Optimize JavaScript Execution Time

How to optimize tamer.web.vercel.app

Next.js SiteScore: 73/100Analyzed January 2026

Optimize JavaScript Execution Time

Medium Impact+6 points estimated

Why It Matters

1.7 seconds of JavaScript execution time is blocking the main thread and delaying Time to Interactive to 8.6 seconds.

How to Fix

Break up long-running JavaScript tasks using React.memo() and useMemo() hooks to prevent unnecessary re-renders. Implement lazy loading with React.lazy() and Suspense for heavy components. Use web workers for CPU-intensive calculations to keep the main thread responsive.

0Needs Improvement

What This Score Means

A score of 73 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

4.8s
Poor

Good: < 2.5s

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

INP

Interaction to Next Paint

101ms
Good

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 73/100, primarily due to excessive JavaScript blocking the main thread for 2.9 seconds. The biggest issue is render-blocking CSS files that delay both First Contentful Paint and Largest Contentful Paint by 750ms, while 207 KiB of unused JavaScript further slows the site. The Largest Contentful Paint takes a concerning 4.8 seconds, mainly caused by a 2.8-second element render delay. Deferring CSS loading, removing unused JavaScript code, and optimizing the build process could improve performance by several seconds and significantly boost user experience.

Other Optimization Recommendations

Eliminate Render-Blocking CSS

High Impact+12 points estimated

Why It Matters:

CSS files are blocking initial render and delaying LCP by 750ms, preventing users from seeing content quickly.

How to Fix:

Inline critical CSS for above-the-fold content in your Next.js pages. Use next/dynamic with ssr: false for non-critical components. Configure next.config.js to extract and defer non-critical CSS chunks using the experimental.css option.

Remove Unused JavaScript Code

High Impact+8 points estimated

Why It Matters:

207 KiB of unused JavaScript is delaying LCP by 300ms and wasting bandwidth on unnecessary code execution.

How to Fix:

Use Next.js dynamic imports to code-split large components and libraries. Analyze your bundle with @next/bundle-analyzer to identify unused dependencies. Implement tree-shaking by using named imports instead of default imports from large libraries.

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Keep Your Site Fast After Optimization

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