LCP
Largest Contentful Paint
3.7s
Needs Improvement
Good: < 2.5s
Measures how long it takes for the main content to appear on screen
Modernize JavaScript Build Target
How to optimize landing.dev.opencals.com
Modernize JavaScript Build Target
High Impact+12 points estimated
Why It Matters
Legacy JavaScript polyfills add 13 KiB and 150ms to LCP for features modern browsers support natively.
How to Fix
Update next.config.js to target modern browsers by setting `target: 'es2020'` and configure browserslist to exclude IE support. Remove unnecessary polyfills for Array.at, Object.hasOwn, and String.trim methods. Use Next.js Modern mode to serve ES6+ to capable browsers.
0Needs Improvement
What This Score Means
A score of 62 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
INP
Interaction to Next Paint
1019ms
Poor
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/React site has poor performance with a score of 62/100. The biggest problem is excessive JavaScript execution time (7.3 seconds) and unused code, with 140 KiB of unnecessary JavaScript being downloaded and a massive 1,470ms of Total Blocking Time that's preventing users from interacting with the page. The site is also using outdated JavaScript polyfills that aren't needed for modern browsers, adding another 13 KiB of waste. Removing unused JavaScript, updating the build configuration to target modern browsers, and breaking up large JavaScript bundles could improve loading times by over 750ms and dramatically enhance user experience.
Other Optimization Recommendations
Remove Unused JavaScript Code
High Impact+18 points estimatedWhy It Matters:
140 KiB of unused JavaScript is delaying LCP by 750ms and blocking user interactions.
How to Fix:
Configure Next.js bundle analyzer to identify unused code with `npm install @next/bundle-analyzer`. Enable tree shaking by ensuring ES6 imports and dynamic imports for heavy components. Split vendor chunks in next.config.js using webpack optimization to defer non-critical libraries until needed.
Eliminate Render-Blocking CSS
Medium Impact+8 points estimatedWhy It Matters:
CSS file is blocking initial render and delaying both FCP and LCP by 100ms.
How to Fix:
Inline critical CSS for above-the-fold content in Next.js pages using `styled-jsx` or CSS-in-JS solutions. Move non-critical CSS to load asynchronously with `next/dynamic` imports. Configure CSS modules to split styles per component and load only what's needed.
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Related Performance Analyses
More Next.js Speed Tests
Next.js Performance Resources
Optimize JavaScript Execution Performance
7.6 seconds of JavaScript execution time creates 2.3 seconds of blocking time, preventing user interactions.
Remove Unused JavaScript Code
140 KiB of unused JavaScript delays LCP by 950ms and blocks user interactions.
Fix Forced Reflow Issues
DOM queries after style changes cause 206ms of forced reflows, degrading rendering performance.
Inline Critical CSS Bundle
Render-blocking CSS delays LCP and FCP by 100ms each, preventing critical content from displaying.