Performance
· 22 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.
855 ms
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
2.60 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
247 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.046
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
1.63 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.
2.61 s
Page Load Progression
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
FJS Execution CostAction5769ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.enel.com/etc.clientlibs/enel-common/clientlibs/clientlib-bundle.lc-81b320f9fffb178b64202b1365875526-lc.min.js | 3633ms | 979ms | 96ms | 3rd |
| https://www.enel.com/ | 1495ms | 2ms | 1ms | 3rd |
| Unattributable | 418ms | 1ms | 0ms | 1st |
| https://assets.adobedtm.com/launch-ENb531171bce964c769bfc582af650ee4a.js | 161ms | 134ms | 16ms | 3rd |
| https://consent.trustarc.com/asset/notice.js/v/v1.7-9089 | 61ms | 43ms | 2ms | 3rd |
FJS BundlesAction16 scripts, 685 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.enel.com/etc.clientlibs/enel-common/clientlibs/clientlib-bundle.lc-81b320f9fffb178b64202b1365875526-lc.min.js | 847 KB | 663 KB (79%) | ✓ | 3rd |
| https://consent.trustarc.com/asset/notice.js/v/v1.7-9089 | 31 KB | 22 KB (71%) | ✓ | 3rd |
| https://assets.adobedtm.com/extensions/EP31dbb9c60e404ba1aa6e746d49be6f29/AppMeasurement.js | 13 KB | — | ✓ | 3rd |
| https://assets.adobedtm.com/58373ae8f4f6/1c927e7a32ab/83adb7e0bcf9/RC25aeefff7bdd4f86a4369efb186ab44e-source.js | 1 KB | — | ✓ | 3rd |
| https://www.enel.com/.rum/@adobe/helix-rum-js@%5E2/dist/micro.js | 1 KB | — | ✓ | 3rd |
| https://assets.adobedtm.com/extensions/EP31dbb9c60e404ba1aa6e746d49be6f29/AppMeasurement_Module_ActivityMap.js | 2 KB | — | ✓ | 3rd |
| https://assets.adobedtm.com/58373ae8f4f6/1c927e7a32ab/83adb7e0bcf9/RCe768bf6d8eff4ea495cab6f62f470268-source.js | 1 KB | — | ✓ | 3rd |
| https://assets.adobedtm.com/58373ae8f4f6/1c927e7a32ab/83adb7e0bcf9/RCdcc61a84fcd84b068d2c39576dedf22d-source.js | 1 KB | — | ✓ | 3rd |
| https://assets.adobedtm.com/58373ae8f4f6/1c927e7a32ab/83adb7e0bcf9/RC1608e7ad1cd541d690e9adec75ebc923-source.js | 1 KB | — | ✓ | 3rd |
| https://www.enel.com/etc.clientlibs/clientlibs/granite/jquery/granite/csrf.lc-652a558c3774088b61b0530c184710d1-lc.min.js | 4 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
FPage Weight InventoryAction69 resources · 2.0 MB · 685 KB savings availableFIX
~684.6 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 69 resources | 2.0 MiB | ||||||
CPage Weight BudgetAction2.0 MB transferred, 69 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
CImage OptimizationAction32 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
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
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
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
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
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
BHTTP/3 (QUIC)HTTP/3 not advertisedREVIEW
CCompression AlgorithmActionMain response served uncompressedREVIEW
BMain HTML Cache-ControlMain HTML max-age=900 (~15min)REVIEW
BServer-Timing ObservabilityNo Server-Timing header foundREVIEW
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 Loading5 fonts (155 KB)PASS
Web fonts
5
155 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+Server Response Intelligence1 server-response signal(s) detectedPASS
AHTTP Cachingmax-age=900 (15 minutes)PASS
max-age=900,stale-while-revalidate=3600
| Directive | Value | Meaning |
|---|---|---|
| max-age | 900 | Cache for 15 minutes |
| stale-while-revalidate | 3600 | Serve stale for 1 hour while fetching fresh |
Network Waterfall69 requests over 3317msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.enel.com www.enel.com | Other | 3633ms | 847 KB | 79% | €39/mo | Costly |
www.enel.com www.enel.com | Other | 1495ms | 51 KB | — | €16/mo | Costly |
assets.adobedtm.com assets.adobedtm.com | Other | 161ms | 92 KB | — | €2/mo | Optional |
consent.trustarc.com consent.trustarc.com | Other | 61ms | 31 KB | 71% | €1/mo | Optional |
These scripts may cost more than they're worth
- www.enel.com adds 3633ms and costs ~€39/month
- www.enel.com adds 1495ms and costs ~€16/month
93% 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
www.enel.com takes 3633ms 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
79% of www.enel.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.enel.com takes 1495ms 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
71% of consent.trustarc.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 Optimization27 images, 399 KB total, 0 KB wastedINFO
Image Optimization Audit
Total Images
27
Total Size
399 KB