Largest Contentful Paint
Good: < 2.5s
Measures how long it takes for the main content to appear on screen
How to optimize don.group.com
116KB of unused JavaScript from tracking scripts and bundled code slows down page parsing and increases load times.
Split the frontend.min.js bundle to load only necessary code initially. Configure Cookiebot to load asynchronously after page load. Defer Matomo tracking script using async/defer attributes or move to a tag manager.
A score of 76 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.
Largest Contentful Paint
Good: < 2.5s
Measures how long it takes for the main content to appear on screen
Interaction to Next Paint
Good: < 200ms
Measures how quickly the page responds to user interactions
Cumulative Layout Shift
Good: < 0.1
Measures visual stability - how much content shifts during page load
This website has moderate performance issues with a score of 76/100, but faces significant Core Web Vitals problems. The biggest issue is a major layout shift (CLS score of 0.625) caused by a hero video that lacks proper sizing, making content jump around as the page loads and creating a poor user experience. Additionally, the site loads a massive 3.4MB of data primarily due to a large video file, and has substantial unused JavaScript and CSS that could be trimmed. Fixing the video sizing issue and optimizing image delivery could improve the Largest Contentful Paint by 150ms and eliminate the disruptive layout shifts entirely.
Why It Matters:
The hero video element causes a massive 0.625 layout shift, severely impacting user experience and CLS score.
How to Fix:
Add explicit CSS dimensions to the hero video element using aspect-ratio: 1120/832 or width/height properties. Set a proper CSS container size before the video loads to reserve the exact space needed.
Why It Matters:
The hero video poster image is 86% oversized for its display dimensions, wasting 60KB and delaying LCP by 150ms.
How to Fix:
Resize the video poster from 1120x832 to match its displayed size of 412x306. Implement responsive images using srcset for different screen sizes. Add fetchpriority='high' to the video element as it's the LCP element.
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More Generic Speed Tests
Critical CSS is blocking First Contentful Paint by 150ms, delaying initial page rendering.
The LCP image lacks priority hints, preventing the browser from optimizing its loading sequence.
Images are oversized and poorly compressed, causing 2.9 second LCP delay and wasting 670 KiB.
JavaScript in header.js is causing 26ms of forced reflows, creating layout thrashing that degrades user experience and blocks the main thread.