Every second slower costs you revenue
Aperion's Performance agent reviews Lighthouse metrics, Core Web Vitals context, available field data, and resource diagnostics - identifying render-blocking resources, oversized images, and slow server responses - then tells you what to fix.
Checks LCP · CLS · INP · FCP · TTFB · Lighthouse scores · Resource audit
The risk is real
Slow pages cost you rankings, sales, and trust
Conversion loss
1 second delay = 7% fewer conversions
Amazon calculated a 1% revenue loss per 100ms delay. For a site doing £1M/year, a 2-second slowdown costs £140,000. Speed is a business metric.
SEO ranking drop
Page speed is a direct Google ranking signal
Core Web Vitals are part of Google's page experience guidance. Poor LCP, CLS, or INP can weaken the user experience and should be fixed before faster competitors feel easier to use.
Bounce rate spike
53% of mobile visits abandoned if > 3s load
More than half of mobile visitors leave before a slow page loads. That is paid traffic, organic traffic, and word-of-mouth referrals - gone.
User frustration
Performance is perceived quality
Slow websites signal low quality, low trust, and low investment. Performance directly shapes brand perception - especially on first visit.
Setup
Performance monitoring in 3 steps
No code changes. No browser extensions. Lighthouse data and available field context for every page.
Add your URL
Aperion captures Lighthouse data and available PageSpeed field context for every page. No code changes or browser extensions required.
AI diagnoses bottlenecks
Every performance metric analysed: render-blocking resources, image optimisation, server response time, caching policies, and third-party script impact.
Get prioritised fixes
Each issue ranked by performance impact. Know which optimisations deliver the biggest score improvements with the least effort.
Performance Coverage
Every metric. Every page.
Aperion reports Lighthouse metrics, Core Web Vitals context, available field data, and resource-level diagnostics - giving you page-level performance evidence, not just a site-wide average.
7
CWV metrics
4
Lighthouse scores
Res.
Resource diagnostics
- LCP - Largest Contentful Paint (Good: < 2.5s, Poor: > 4s)
- CLS - Cumulative Layout Shift (Good: < 0.1, Poor: > 0.25)
- INP - Interaction to Next Paint (Good: < 200ms, Poor: > 500ms)
- FCP - First Contentful Paint (Good: < 1.8s)
- TTFB - Time to First Byte (Good: < 800ms)
- Performance score (0-100)
- Accessibility score (0-100)
- Best Practices score (0-100)
- SEO score (0-100)
- Tested across mobile and desktop device profiles
- Image optimisation - format, compression, sizing
- Render-blocking JavaScript and CSS
- Unused JavaScript (kilobytes saved)
- Font loading strategy and display swap
- Third-party script impact on load time
- Cache-Control and Expires header coverage
- TTFB - server response time
- Compression - gzip and Brotli support
- HTTP/2 and HTTP/3 protocol usage
- CDN usage and edge caching
- Redirect count and redirect chains
- DNS lookup time
Audit output
See exactly what an Aperion performance report looks like
Structured, machine-readable reports with every metric result, resource diagnosis, and prioritised fix instructions.
Performance overview
Lighthouse performance score is 54 - in the "needs improvement" range. LCP, CLS, and FCP are all outside good thresholds, creating user experience risk and likely conversion friction on slower visits.
54
Lighthouse score
Poor
Performance grade
{
"lighthouse_score": 54,
"lcp": "3.8s",
"cls": 0.14,
"inp": "220ms",
"fcp": "2.9s",
"ttfb": "1.2s",
"performance_grade": "poor"
}Core Web Vitals breakdown
LCP and CLS are both poor in this lab run. INP should be checked against field data when available, while LCP is the largest visible opportunity in the current Lighthouse report.
Estimated ranking impact
Fixing LCP alone could move 3+ ranking positions on competitive queries
{
"lcp_status": "poor",
"cls_status": "poor",
"inp_status": "needs-improvement",
"fcp_status": "needs-improvement",
"all_vitals_pass": false
}Lighthouse category scores
Performance at 54 needs significant improvement. Accessibility and Best Practices are in the moderate range. SEO score is strong at 91, suggesting the core on-page elements are in order.
Performance
54
Accessibility
78
Best Practices
83
SEO
91
{
"performance": 54,
"accessibility": 78,
"best_practices": 83,
"seo": 91,
"tested_device": "mobile"
}Resource diagnostics
Six render-blocking resources are delaying the start of page rendering. 284KB of unused JavaScript is being loaded on every page. Twelve unoptimised images are adding 4.8MB of unnecessary weight.
- 6 render-blocking resources
- 284 KB unused JavaScript
- 12 unoptimised images
- 4.8 MB total page weight
{
"render_blocking_resources": 6,
"unused_javascript_kb": 284,
"unoptimised_images": 12,
"total_page_weight_kb": 4821
}Prioritised fix plan
Eliminating render-blocking JavaScript is the highest-impact fix - estimated to improve LCP by 1.4 seconds and boost the Lighthouse score by 18 points. Medium effort with a large return.
- Estimated LCP gain: 1.4 seconds
- Estimated score gain: +18 points
- Effort: medium
- Highest priority of 6 issues
{
"top_fix": "render-blocking JS",
"estimated_lcp_gain": "1.4s",
"estimated_score_gain": 18,
"effort": "medium"
}Frequently asked questions
- Aperion reports Lighthouse metrics, Core Web Vitals context, available PageSpeed field data, Lighthouse category scores, and resource-level diagnostics including render-blocking resources, unused JavaScript, unoptimised images, page weight, caching headers, compression, and third-party script impact. Lab metrics are clearly treated as lab data, and field responsiveness is reported when available.
- The relationship between speed and conversions is direct and measurable. Amazon found a 1% revenue loss per 100ms of added latency. Google data shows that pages loading in 1-3 seconds have a 32% higher bounce rate than pages loading in under 1 second. For mobile, 53% of visitors abandon a page that takes more than 3 seconds to load. Every additional second of load time is a conversion loss multiplier.
- Core Web Vitals are Google page experience metrics. LCP measures loading performance, CLS measures visual stability, and INP measures responsiveness from real-user field data when available. Lighthouse lab data can help diagnose issues, but it is not the same as real-user INP.
- Lighthouse scores from 0-100 are colour-coded: 0-49 is poor (red), 50-89 needs improvement (amber), and 90-100 is good (green). For the Performance category specifically, a score above 90 is the target. Low scores usually indicate user experience and implementation issues worth investigating. Aperion tracks Lighthouse scores for Performance, Accessibility, Best Practices, and SEO.
- Performance regressions are introduced with every deployment - a new JavaScript bundle, a larger hero image, or a new third-party script can all degrade Core Web Vitals. Aperion supports scheduled monitoring so you are notified immediately when a regression is detected. For most sites, weekly monitoring is a minimum. For e-commerce or high-traffic sites, daily monitoring ensures regressions are caught before they compound into significant revenue loss.
- Yes. Aperion's Performance agent goes beyond reporting a score - it identifies the specific resources causing slowness. This includes render-blocking JavaScript and CSS files, oversized or unoptimised images (with estimated savings), unused JavaScript bundles (in kilobytes), slow server response times, missing compression, inefficient caching policies, and third-party script impact. Each issue is ranked by its estimated performance gain, so you know exactly where to focus effort.
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