Performance
· 17 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.Performance-focused optimization plan with CWV assessment, top offenders, and time estimates
First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.
4.60 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
5.10 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
177 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.000
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
5.33 s
Time to Interactive Time to Interactive — how long until the page is fully interactive and responds to user input. Under 3.8s is good.
5.11 s
Page Load Progression
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CJS Execution CostAction1134ms total JS executionREVIEW
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| Unattributable | 578ms | 100ms | 0ms | 3rd |
| https://www.amazontrust.com/assets/entry.client-JAa7dmjd.js | 440ms | 419ms | 2ms | 3rd |
| https://www.amazontrust.com/ | 116ms | 23ms | 6ms | 3rd |
BJS Bundles34 scripts, 114 KB unusedREVIEW
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.amazontrust.com/assets/root-ejUo2Bfm.js | 59 KB | 42 KB (72%) | ✓ | 3rd |
| https://www.amazontrust.com/assets/index-DT_-TPwo.js | 42 KB | 26 KB (64%) | ✓ | 3rd |
| https://www.amazontrust.com/assets/cloudwatchRum-BavfjJze.js | 46 KB | 24 KB (52%) | ✓ | 3rd |
| https://www.amazontrust.com/assets/entry.client-JAa7dmjd.js | 57 KB | 22 KB (40%) | ✓ | 3rd |
| https://www.amazontrust.com/assets/handle-key-PSknjZbb.js | 4 KB | — | ✓ | 3rd |
| https://www.amazontrust.com/assets/internal-DUJKdEBb.js | 1 KB | — | ✓ | 3rd |
| https://www.amazontrust.com/assets/useTranslation-D73jT0OV.js | 2 KB | — | ✓ | 3rd |
| https://www.amazontrust.com/assets/constants-OVDVSXrx.js | 2 KB | — | ✓ | 3rd |
| https://www.amazontrust.com/assets/analytics-funnel-BLGvchBv.js | 43 KB | — | ✓ | 3rd |
| https://www.amazontrust.com/assets/use-sticky-header-Du51T5yF.js | 9 KB | — | ✓ | 3rd |
Consider code splitting or tree shaking to reduce unused code.
This bundle has high unused code — code-split or tree-shake to ship only what executes.
Source: web.dev / Lighthouse coverage
Consider code splitting or tree shaking to reduce unused code.
This bundle has high unused code — code-split or tree-shake to ship only what executes.
Source: web.dev / Lighthouse coverage
Consider code splitting or tree shaking to reduce unused code.
This bundle has high unused code — code-split or tree-shake to ship only what executes.
Source: web.dev / Lighthouse coverage
Consider code splitting or tree shaking to reduce unused code.
This bundle has high unused code — code-split or tree-shake to ship only what executes.
Source: web.dev / Lighthouse coverage
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
No green hosting detected
A+Page Weight Budget625 KB transferred, 63 requestsPASS
A+Text CompressionAll text resources are compressedPASS
AImage Optimization2 images, 0 KB saveablePASS
Set explicit width and height to prevent CLS.
Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.
Source: web.dev / Core Web Vitals
A+Font Loading3 fonts (49 KB)PASS
Web fonts
3
49 KB total
Render-blocking
0
of 3
Dominant font-display
swap
Most common across fonts
Font loading timeline
Optimization checklist
- Preload critical fonts (priority=high)
- Use woff2 format for all fonts
- Set font-display to swap, optional, or fallback
- Subset large fonts (≤100 KB each)
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource Hints2 hints, 0 missing preconnectsPASS
Current Resource Hints
2 resource hints configured
APage Weight Inventory63 resources · 625 KB · 114 KB savings availablePASS
~114.4 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 63 resources | 625.4 KiB | ||||||
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
Network Waterfall63 requests over 2711msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
Unattributable Unattributable | Other | 578ms | 0 KB | — | €6/mo | Costly |
www.amazontrust.com www.amazontrust.com | Other | 440ms | 57 KB | 40% | €5/mo | Costly |
www.amazontrust.com www.amazontrust.com | Other | 116ms | 5 KB | — | €1/mo | Optional |
These scripts may cost more than they're worth
- Unattributable adds 578ms and costs ~€6/month
- www.amazontrust.com adds 440ms and costs ~€5/month
100% of JavaScript execution time is spent on third-party scripts. Consider auditing which scripts are essential.
When third-party JS execution time exceeds your own, performance gains from frontend work are capped by code you don't own.
Learn more ▾ ▴
Every millisecond of third-party JS competes with your own for main-thread time. If their share is bigger than yours, optimization on your code base barely moves the needle. Audit, defer, or remove third-parties before further frontend optimization. Use Lighthouse's third-party audit to identify the worst offenders.
Source: web.dev
Unattributable takes 578ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev
www.amazontrust.com takes 440ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.
This script has high main-thread execution time — optimize hot paths or defer.
Source: web.dev