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.
6.16 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
8.63 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
959 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
2.011
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
6.56 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.
14.60 s
Page Load Progression
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
FJS Execution CostAction4605ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://kosmos-prod.react.gammacdn.com/react-18-2-0-prod.js | 1797ms | 1635ms | 1ms | 3rd |
| https://kosmos-prod.react.gammacdn.com/app.modern.df06e6174f742cabbe11.js | 727ms | 477ms | 118ms | 3rd |
| Unattributable | 458ms | 98ms | 0ms | 1st |
| https://www.googletagmanager.com/gtag/js?id=G-NFJNW2QT0H&cx=c>m=4e6bb1 | 309ms | 238ms | 53ms | 3rd |
| https://www.blacksonblondes.com/sfw | 297ms | 4ms | 0ms | 3rd |
| https://www.blacksonblondes.com/cdn-cgi/scripts/7d0fa10a/cloudflare-static/rocket-loader.min.js | 284ms | 104ms | 9ms | 3rd |
| https://kosmos-prod.react.gammacdn.com/ajv.modern.b283ba07fa118e350850.js | 258ms | 230ms | 9ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-NLP9VR8 | 180ms | 144ms | 23ms | 3rd |
| https://cdn.izooto.com/scripts/sdk/main.js | 152ms | 102ms | 42ms | 3rd |
| https://d3a3ewgd1iewwz.cloudfront.net/promomessages/dist.js | 85ms | 67ms | 10ms | 3rd |
Showing top 10 of 11 scripts
DJS BundlesAction23 scripts, 486 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://kosmos-prod.react.gammacdn.com/app.modern.df06e6174f742cabbe11.js | 456 KB | 263 KB (58%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-NFJNW2QT0H&cx=c>m=4e6bb1 | 176 KB | 75 KB (43%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-NLP9VR8 | 126 KB | 63 KB (50%) | ✓ | 3rd |
| https://cdn.izooto.com/scripts/sdk/main.js | 87 KB | 61 KB (70%) | ✓ | 3rd |
| https://static01-cms-fame.gammacdn.com/c/minify/70/7534ebf7091fdface5ec3afea1ca4e.js | 35 KB | 24 KB (71%) | ✓ | 3rd |
| https://kosmos-prod.react.gammacdn.com/react-18-2-0-prod.js | 5 KB | — | ✓ | 3rd |
| https://d3a3ewgd1iewwz.cloudfront.net/promomessages/dist.js | 38 KB | — | ✓ | 3rd |
| https://www.blacksonblondes.com/cdn-cgi/scripts/7d0fa10a/cloudflare-static/rocket-loader.min.js | 4 KB | — | ✓ | 3rd |
| https://kosmos-prod.react.gammacdn.com/ajv.modern.b283ba07fa118e350850.js | 35 KB | — | ✓ | 3rd |
| https://kosmos-prod.react.gammacdn.com/legal-client.modern.fa5666225724a2fcd047.js | 2 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 InventoryAction98 resources · 1.7 MB · 486 KB savings availableFIX
~486.0 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 98 resources | 1.7 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CPage Weight BudgetAction1.7 MB transferred, 98 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
Subset fonts to include only used characters, or switch to system font stacks.
Font payload is large — subset to used glyphs only, or fall back to system fonts (zero load time).
Source: web.dev font loading
BImage Optimization37 images, 0 KB saveableREVIEW
CDocument CompressionActionDocument response served uncompressedREVIEW
BMain HTML Cache-ControlNo Cache-Control header on main HTML responseREVIEW
BServer-Timing ObservabilityNo Server-Timing header foundREVIEW
BJavaScript Blocking2 JS blocking issue(s) detectedREVIEW
A+Text CompressionAll text resources are compressedPASS
A+Font Loading3 fonts (299 KB)PASS
Web fonts
3
299 KB total
Render-blocking
0
of 3
Dominant font-display
swap
Most common across fonts
Font loading timeline
- Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
- Subset this font — over 100 KB suggests Latin Extended or full glyph coverage that most pages don't need
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)
Fixing the unchecked items could save ~103 KB and ~206 ms
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource Hints11 hints, 0 missing preconnectsPASS
Current Resource Hints
11 resource hints configured
A+HTTP/3 (QUIC)HTTP/3 advertised via Alt-SvcPASS
AAsset Compression1 of 2 asset hosts still on gzipPASS
A+LCP Image PreloadLCP preload audit not availablePASS
A+Server Response Intelligence1 server-response signal(s) detectedPASS
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
ACSS Performance Depth1 CSS depth issue(s) detectedPASS
A+Green HostingWhether the site is served from green-energy infrastructurePASS
Green Hosting
This site is hosted on green energy infrastructure
Provider: Cloudflare
Network Waterfall98 requests over 4539msINFO
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 | 1797ms | 5 KB | — | €20/mo | Costly |
kosmos-prod.react.gammacdn.com kosmos-prod.react.gammacdn.com | Other | 727ms | 456 KB | 58% | €8/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 309ms | 176 KB | 43% | €3/mo | Costly |
www.blacksonblondes.com www.blacksonblondes.com | Other | 297ms | 15 KB | — | €3/mo | Costly |
www.blacksonblondes.com www.blacksonblondes.com | Other | 284ms | 4 KB | — | €3/mo | Costly |
kosmos-prod.react.gammacdn.com kosmos-prod.react.gammacdn.com | Other | 258ms | 35 KB | — | €3/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 180ms | 126 KB | 50% | €2/mo | Optional |
cdn.izooto.com cdn.izooto.com | Other | 152ms | 87 KB | 70% | €2/mo | Optional |
d3a3ewgd1iewwz.cloudfront.net d3a3ewgd1iewwz.cloudfront.net | Other | 85ms | 38 KB | — | €1/mo | Optional |
kosmos-prod.react.gammacdn.com kosmos-prod.react.gammacdn.com | Other | 59ms | 26 KB | — | €1/mo | Optional |
These scripts may cost more than they're worth
- kosmos-prod.react.gammacdn.com adds 1797ms and costs ~€20/month
- kosmos-prod.react.gammacdn.com adds 727ms and costs ~€8/month
- Google Tag Manager adds 309ms and costs ~€3/month
- www.blacksonblondes.com adds 297ms and costs ~€3/month
- www.blacksonblondes.com adds 284ms and costs ~€3/month
- kosmos-prod.react.gammacdn.com adds 258ms 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 1797ms 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 727ms 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
58% 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
Google Tag Manager takes 309ms 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.blacksonblondes.com takes 297ms 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.blacksonblondes.com takes 284ms 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 258ms 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
50% of Google Tag Manager'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
70% 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
Image Optimization74 images, 0 KB total, 0 KB wastedINFO
Image Optimization Audit
Total Images
74
Total Size
0 KB
Oversized
2