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.
11.58 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
18.60 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
1.18 s
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.
11.58 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.
19.51 s
Page Load Progression
375 ms 750 ms 1.1 s 1.5 s 1.9 s 2.2 s
2.6 s 3.0 sDPage Weight BudgetAction2.4 MB transferred, 186 requestsFIX
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
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
High HTTP request count — bundling, sprite-ing, and HTTP/2 server push can reduce per-request overhead.
Source: web.dev
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
FJS Execution CostAction7263ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://cerebro-platform.sky.it/static/content/sp/js/common.js?async&seed=AAALNbedAQAA5bC2LTkP75sTg1ADGv6F_7irX-HpCaaN-E_h7qUmS7juXFt4&IshafTpPXs--z=q | 1881ms | 1794ms | 18ms | 3rd |
| https://www.sky.it/_next/static/chunks/framework-35048067b0fccd1f.js | 1461ms | 730ms | 20ms | 3rd |
| Unattributable | 750ms | 22ms | 0ms | 3rd |
| https://www.datadoghq-browser-agent.com/eu1/v6/datadog-rum.js | 421ms | 376ms | 11ms | 3rd |
| https://cmp.sky.it/Notice.8f529.js | 403ms | 245ms | 26ms | 3rd |
| https://www.sky.it/ | 374ms | 54ms | 3ms | 3rd |
| https://assets.adobedtm.com/27331c16692c/d6621d9f42c4/launch-19ddb1c8c4b6.min.js | 351ms | 265ms | 43ms | 3rd |
| https://www.sky.it/_next/static/chunks/281c3f4d-41ed0b65a9fdac4d.js | 290ms | 96ms | 6ms | 3rd |
| https://www.sky.it/_next/static/chunks/pages/index-65f273f2d870ca8e.js | 268ms | 239ms | 0ms | 3rd |
| https://cdn.privacy-mgmt.com/wrapperMessagingWithoutDetection.js | 231ms | 144ms | 19ms | 3rd |
Showing top 10 of 18 scripts
FJS BundlesAction121 scripts, 448 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.sky.it/_next/static/chunks/pages/_app-71ef376c6516b45f.js | 175 KB | 109 KB (62%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-RWMN51KW03 | 176 KB | 63 KB (36%) | ✓ | 3rd |
| https://cmp.sky.it/Notice.8f529.js | 91 KB | 61 KB (67%) | ✓ | 3rd |
| https://ctlive.sky.it/livechat/SKY/amdlib/jquery-ui-dist/jquery-ui.min.js?define=__ctliveDefine | 67 KB | 59 KB (89%) | ✓ | 3rd |
| https://ctlive.sky.it/livechat/SKY/widget/widget.js | 63 KB | 58 KB (93%) | ✗ | 3rd |
| https://www.datadoghq-browser-agent.com/eu1/v6/datadog-rum.js | 58 KB | 31 KB (53%) | ✓ | 3rd |
| https://cdn.privacy-mgmt.com/wrapperMessagingWithoutDetection.js | 54 KB | 23 KB (44%) | ✓ | 3rd |
| https://www.sky.it/_next/static/chunks/framework-35048067b0fccd1f.js | 59 KB | 22 KB (38%) | ✓ | 3rd |
| https://ctlive.sky.it/livechat/SKY/lib/core/liveChatProtocol.js | 24 KB | 21 KB (88%) | ✗ | 3rd |
| https://www.sky.it/_next/static/chunks/7548.05a9e44dbb2770d0.js | 6 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 InventoryAction186 resources · 2.4 MB · 448 KB savings availableFIX
~447.6 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 186 resources | 2.4 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
BImage Optimization20 images, 0 KB saveableREVIEW
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
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
No green hosting detected
A+Text CompressionAll text resources are compressedPASS
A+Font Loading16 fonts (563 KB)PASS
Web fonts
16
563 KB total
Render-blocking
0
of 16
Dominant font-display
swap
Most common across fonts
Font loading timeline
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
- Convert to woff2 for ~30% smaller file size
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 ~66 KB and ~132 ms
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource Hints20 hints, 0 missing preconnectsPASS
Current Resource Hints
20 resource hints configured
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
Network Waterfall186 requests over 3949msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
cerebro-platform.sky.it cerebro-platform.sky.it | Other | 1881ms | 160 KB | — | €30/mo | Costly |
www.sky.it www.sky.it | Other | 1461ms | 59 KB | 38% | €23/mo | Costly |
Unattributable Unattributable | Other | 750ms | 0 KB | — | €12/mo | Costly |
www.datadoghq-browser-agent.com www.datadoghq-browser-agent.com | Other | 421ms | 58 KB | 53% | €7/mo | Costly |
cmp.sky.it cmp.sky.it | Other | 403ms | 91 KB | 67% | €6/mo | Costly |
www.sky.it www.sky.it | Other | 374ms | 72 KB | — | €6/mo | Costly |
assets.adobedtm.com assets.adobedtm.com | Other | 351ms | 74 KB | — | €6/mo | Costly |
www.sky.it www.sky.it | Other | 290ms | 20 KB | — | €5/mo | Costly |
www.sky.it www.sky.it | Other | 268ms | 1 KB | — | €4/mo | Costly |
cdn.privacy-mgmt.com cdn.privacy-mgmt.com | Other | 231ms | 54 KB | 44% | €4/mo | Costly |
www.sky.it www.sky.it | Other | 181ms | 175 KB | 62% | €3/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 138ms | 176 KB | 36% | €2/mo | Optional |
ctlive.sky.it ctlive.sky.it | Other | 112ms | 67 KB | 89% | €2/mo | Optional |
www.sky.it www.sky.it | Other | 92ms | 34 KB | — | €1/mo | Optional |
ctlive.sky.it ctlive.sky.it | Other | 85ms | 30 KB | — | €1/mo | Optional |
ctlive.sky.it ctlive.sky.it | Other | 83ms | 4 KB | — | €1/mo | Optional |
www.sky.it www.sky.it | Other | 80ms | 6 KB | — | €1/mo | Optional |
ctlive.sky.it ctlive.sky.it | Other | 62ms | 63 KB | 93% | €1/mo | Optional |
These scripts may cost more than they're worth
- cerebro-platform.sky.it adds 1881ms and costs ~€30/month
- www.sky.it adds 1461ms and costs ~€23/month
- Unattributable adds 750ms and costs ~€12/month
- www.datadoghq-browser-agent.com adds 421ms and costs ~€7/month
- cmp.sky.it adds 403ms and costs ~€6/month
- www.sky.it adds 374ms and costs ~€6/month
- assets.adobedtm.com adds 351ms and costs ~€6/month
- www.sky.it adds 290ms and costs ~€5/month
- www.sky.it adds 268ms and costs ~€4/month
- cdn.privacy-mgmt.com adds 231ms and costs ~€4/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
cerebro-platform.sky.it takes 1881ms 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.sky.it takes 1461ms 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
Unattributable takes 750ms 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.datadoghq-browser-agent.com takes 421ms 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
53% of www.datadoghq-browser-agent.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
cmp.sky.it takes 403ms 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
67% of cmp.sky.it'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.sky.it takes 374ms 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
assets.adobedtm.com takes 351ms 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.sky.it takes 290ms 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.sky.it takes 268ms 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.privacy-mgmt.com takes 231ms 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
62% of www.sky.it'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
89% of ctlive.sky.it'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
93% of ctlive.sky.it'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