Performance
· 27 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.
6.17 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
7.82 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
1.75 s
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
2.885
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
37.02 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.
14.66 s
Page Load Progression
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
FJS Execution CostAction5820ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://kosmos-prod.react.gammacdn.com/react-18-2-0-prod.js | 1960ms | 1816ms | 2ms | 3rd |
| https://kosmos-prod.react.gammacdn.com/app.modern.185d5ea69026b0168e4d.js | 1053ms | 664ms | 225ms | 3rd |
| Unattributable | 591ms | 94ms | 0ms | 1st |
| https://www.roccosiffredi.com/sfw | 564ms | 5ms | 1ms | 3rd |
| https://www.roccosiffredi.com/cdn-cgi/scripts/7d0fa10a/cloudflare-static/rocket-loader.min.js | 389ms | 150ms | 18ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-HCRTF4K1E5&cx=c>m=4e69n1 | 287ms | 202ms | 71ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-TWVMJ48 | 273ms | 205ms | 54ms | 3rd |
| https://cdn.izooto.com/scripts/sdk/main.js | 208ms | 140ms | 55ms | 3rd |
| https://kosmos-prod.react.gammacdn.com/ajv.modern.7550aa334019432050ac.js | 197ms | 181ms | 16ms | 3rd |
| https://d3a3ewgd1iewwz.cloudfront.net/promomessages/dist.js | 158ms | 132ms | 16ms | 3rd |
Showing top 10 of 12 scripts
DJS BundlesAction23 scripts, 469 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://kosmos-prod.react.gammacdn.com/app.modern.185d5ea69026b0168e4d.js | 442 KB | 246 KB (56%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-HCRTF4K1E5&cx=c>m=4e69n1 | 163 KB | 72 KB (44%) | ✓ | 3rd |
| https://cdn.izooto.com/scripts/sdk/main.js | 97 KB | 66 KB (68%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-TWVMJ48 | 129 KB | 64 KB (50%) | ✓ | 3rd |
| https://static01-cms-fame.gammacdn.com/c/minify/80/6628daca02f400be6ec1cae12b1bdf.js | 34 KB | 22 KB (66%) | ✓ | 3rd |
| https://kosmos-prod.react.gammacdn.com/react-18-2-0-prod.js | 4 KB | — | ✓ | 3rd |
| https://d3a3ewgd1iewwz.cloudfront.net/promomessages/dist.js | 38 KB | — | ✓ | 3rd |
| https://www.roccosiffredi.com/cdn-cgi/scripts/7d0fa10a/cloudflare-static/rocket-loader.min.js | 4 KB | — | ✓ | 3rd |
| https://kosmos-prod.react.gammacdn.com/legal-client.modern.944c9843f2bd6f2649a8.js | 2 KB | — | ✓ | 3rd |
| https://kosmos-prod.react.gammacdn.com/ajv.modern.7550aa334019432050ac.js | 34 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
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
FPage Weight InventoryAction89 resources · 1.5 MB · 469 KB savings availableFIX
~469.3 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 89 resources | 1.5 MiB | ||||||
BPage Weight Budget1.5 MB transferred, 89 requestsREVIEW
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
JavaScript bundle is large — code-split routes and lazy-load off-screen components to defer.
Source: web.dev
BImage Optimization29 images, 0 KB saveableREVIEW
Set explicit width and height to prevent CLS.
Performance issues directly impact user engagement and conversion rates.
BHTTP/3 (QUIC)HTTP/3 not advertisedREVIEW
BDocument CompressionDocument response uses gzip; brotli would be ~20% smallerREVIEW
BServer-Timing ObservabilityNo Server-Timing header foundREVIEW
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
No green hosting detected
BHTTP Cachingno-cacheREVIEW
no-cache
| Directive | Value | Meaning |
|---|---|---|
| no-cache | — | Cache but always revalidate first |
A+Text CompressionAll text resources are compressedPASS
A+Font Loading5 fonts (122 KB)PASS
Web fonts
5
122 KB total
Render-blocking
0
of 5
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 HintsNo optimization neededPASS
A+LCP Image PreloadLCP preload audit not availablePASS
A+Main HTML Cache-ControlMain HTML uses no-cache -- safe revalidate-on-request policyPASS
AServer Response Intelligence2 server-response signal(s) detectedPASS
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
AJavaScript Blocking1 JS blocking issue(s) detectedPASS
A+CSS Performance DepthNo CSS performance depth issues detectedPASS
Asset CompressionNo text asset hosts to measureINFO
Network Waterfall89 requests over 26098msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
kosmos-prod.react.gammacdn.com kosmos-prod.react.gammacdn.com | Other | 1960ms | 4 KB | — | $26/mo | Costly |
kosmos-prod.react.gammacdn.com kosmos-prod.react.gammacdn.com | Other | 1053ms | 442 KB | 56% | $14/mo | Costly |
www.roccosiffredi.com www.roccosiffredi.com | Other | 564ms | 15 KB | — | $7/mo | Costly |
www.roccosiffredi.com www.roccosiffredi.com | Other | 389ms | 4 KB | — | $5/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 287ms | 163 KB | 44% | $4/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 273ms | 129 KB | 50% | $4/mo | Costly |
cdn.izooto.com cdn.izooto.com | Other | 208ms | 97 KB | 68% | $3/mo | Costly |
kosmos-prod.react.gammacdn.com kosmos-prod.react.gammacdn.com | Other | 197ms | 34 KB | — | $3/mo | Optional |
d3a3ewgd1iewwz.cloudfront.net d3a3ewgd1iewwz.cloudfront.net | Other | 158ms | 38 KB | — | $2/mo | Optional |
kosmos-prod.react.gammacdn.com kosmos-prod.react.gammacdn.com | Other | 79ms | 25 KB | — | $1/mo | Optional |
static01-cms-fame.gammacdn.com static01-cms-fame.gammacdn.com | Other | 61ms | 34 KB | 66% | $1/mo | Optional |
These scripts may cost more than they're worth
- kosmos-prod.react.gammacdn.com adds 1960ms and costs ~$26/month
- kosmos-prod.react.gammacdn.com adds 1053ms and costs ~$14/month
- www.roccosiffredi.com adds 564ms and costs ~$7/month
- www.roccosiffredi.com adds 389ms and costs ~$5/month
- Google Tag Manager adds 287ms and costs ~$4/month
- Google Tag Manager adds 273ms and costs ~$4/month
- cdn.izooto.com adds 208ms and costs ~$3/month
90% 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
kosmos-prod.react.gammacdn.com takes 1960ms 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
kosmos-prod.react.gammacdn.com takes 1053ms 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
56% of kosmos-prod.react.gammacdn.com's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
www.roccosiffredi.com takes 564ms 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.roccosiffredi.com takes 389ms 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
Google Tag Manager takes 287ms 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
Google Tag Manager takes 273ms 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
cdn.izooto.com takes 208ms 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
68% of cdn.izooto.com's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
66% of static01-cms-fame.gammacdn.com's code is unused. The script may be loading features you don't use.
Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.
Source: web.dev
Image Optimization33 images, 988 KB total, 0 KB wastedINFO
Image Optimization Audit
Total Images
33
Total Size
988 KB