LCP
Largest Contentful Paint
6.1s
Poor
Good: < 2.5s
Measures how long it takes for the main content to appear on screen
Optimize JavaScript Execution and Bundle Size
How to optimize joebrowns.co.uk
Generic SiteScore: 41/100Analyzed January 2026
Optimize JavaScript Execution and Bundle Size
High Impact+25 points estimated
Why It Matters
JavaScript execution time of 6.5 seconds is blocking the main thread and causing 1,610ms Total Blocking Time, severely impacting user interactivity.
How to Fix
Remove or defer the heavy Noibu analytics script (2.8s execution time). Implement code splitting to load only critical JavaScript initially. Use tree shaking to eliminate 835 KiB of unused JavaScript, especially from reCAPTCHA and Google Tag Manager bundles.
0Poor
What This Score Means
A score of 41 falls in the "Poor" 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
277ms
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 Joe Browns e-commerce site has severe performance issues with a critically low score of 41/100. The biggest problem is excessive JavaScript execution taking 6.5 seconds to complete, which is blocking the main thread for over 10 seconds and causing a painfully slow Time to Interactive of 34 seconds. The site is loading 835 KB of unused JavaScript (particularly from Google reCAPTCHA and analytics scripts) and suffering from poor caching strategies that could save 408 KB on repeat visits. Reducing JavaScript payload sizes, removing unused code, and optimizing the main thread work could dramatically improve this site's performance and user experience.
Other Optimization Recommendations
Optimize Image Delivery and Formats
High Impact+15 points estimatedWhy It Matters:
Images are causing 150ms LCP delay and consuming 244 KiB of unnecessary bandwidth, directly impacting page load performance.
How to Fix:
Convert large images to WebP or AVIF format for 30-70% size reduction. Implement responsive images with proper srcset attributes. Add fetchpriority='high' to the LCP image and ensure it's not lazy loaded. Compress the 150KB shop-all-sale-homeware.jpg image.
Add Explicit Image Dimensions
Medium Impact+8 points estimatedWhy It Matters:
Missing width and height attributes on images cause layout shifts during loading, negatively affecting Cumulative Layout Shift scores.
How to Fix:
Add explicit width and height attributes to all images, especially the hero image and mobile-only images. Set CSS aspect-ratio property to maintain responsive behavior while preventing layout shifts. Update image templates in your Magento theme files.
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Related Performance Analyses
More Generic Speed Tests
Generic Performance Resources
Enable Advanced Browser Caching
Optimizing cache headers ensures consistently fast repeat visits and maintains your excellent performance score.
Implement Critical Resource Preloading
With a perfect performance score, preloading key resources can further optimize LCP for varying network conditions.
Optimize Mobile Viewport Meta Tag
Current viewport configuration causes 300ms tap delays on mobile interactions, directly impacting INP scores.
Add Explicit Image Dimensions
Images without width/height attributes cause layout shifts and poor user experience as they load.
Frequently Asked Questions
Keep Your Site Fast After Optimization
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