LCP
Largest Contentful Paint
13.9s
Poor
Good: < 2.5s
Measures how long it takes for the main content to appear on screen
Eliminate Render Blocking CSS
How to optimize accept.nioz.nl
Eliminate Render Blocking CSS
High Impact+25 points estimated
Why It Matters
CSS files are blocking the initial page render, delaying both FCP by 5.7s and LCP by 13.9s with 450ms potential savings.
How to Fix
Inline critical above-the-fold CSS directly in the HTML head. Split the large CSS bundle and defer non-critical styles using media='print' onload technique. Remove unused CSS rules which account for 87% of the main stylesheet (94KB savings).
0Needs Improvement
What This Score Means
A score of 54 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
451ms
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 website has poor performance with a score of 54/100, indicating significant user experience issues. The biggest problem is extremely slow page loading, with the Largest Contentful Paint taking 13.9 seconds and First Contentful Paint at 5.7 seconds - both far exceeding acceptable standards. The primary culprits are massive amounts of unused CSS (93 KiB) and JavaScript (478 KiB) that are blocking the initial page render, plus inefficient caching policies that force users to re-download large files on every visit. Removing unused code, implementing proper caching headers, and optimizing the oversized images could easily improve the performance score by 30+ points and dramatically reduce loading times from nearly 14 seconds to under 3 seconds.
Other Optimization Recommendations
Reduce Unused JavaScript Bundles
High Impact+20 points estimatedWhy It Matters:
478KB of unused JavaScript is consuming network bandwidth and causing 2.4s of main thread blocking time.
How to Fix:
Implement code splitting to load only necessary JavaScript per page. Remove unused citation and bibliography libraries (citeproc, bibtex plugins) if not needed. Use dynamic imports for components like lottie animations that aren't immediately required.
Optimize Images and Add Dimensions
Medium Impact+12 points estimatedWhy It Matters:
Images lack explicit dimensions causing layout shifts and are oversized by 509KB, potentially affecting user experience.
How to Fix:
Add explicit width and height attributes to all img elements to prevent CLS. Convert the main carousel image from PNG to WebP format for 314KB savings. Implement responsive images with proper srcset attributes to serve appropriately sized images for different screen sizes.
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Related Performance Analyses
More Generic Speed Tests
Generic Performance Resources
Implement Proper Font Loading
Web fonts cause layout shifts and block text rendering, delaying FCP by 610ms.
Optimize Critical Resource Loading
Render-blocking CSS delays FCP by 390ms and unused JavaScript wastes 97KB of bandwidth.
Fix Image Layout Shifts
Unsized images cause 0.417 CLS score, severely hurting user experience and Core Web Vitals.
Implement JavaScript Code Splitting
Loading all JavaScript upfront blocks rendering even for components not immediately visible to users.