Performance
· 26 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.
4.07 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
16.00 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
1.46 s
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.156
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
5.53 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.
16.22 s
Page Load Progression
FPage Weight BudgetAction2.8 MB transferred, 79 requestsFIX
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Image bandwidth is high — modern formats (WebP/AVIF) and resizing typically cut it 50%+.
Source: web.dev
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
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
FJS Execution CostAction25849ms 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 | 15306ms | 3725ms | 343ms | 3rd |
| https://www.enel.com/ | 7740ms | 7ms | 2ms | 3rd |
| Unattributable | 1801ms | 4ms | 0ms | 1st |
| https://assets.adobedtm.com/launch-ENb531171bce964c769bfc582af650ee4a.js | 619ms | 530ms | 51ms | 3rd |
| https://consent.trustarc.com/asset/notice.js/v/v1.7-9089 | 200ms | 153ms | 11ms | 3rd |
| https://consent.trustarc.com/notice?domain=enel.com&c=teconsent&js=nj¬iceType=bb>m=1&text=true&language=en | 113ms | 52ms | 4ms | 3rd |
| https://www.enel.com/etc.clientlibs/enel-common/clientlibs/clientlib-bundle.lc-84662e0e38777d08aa6397720c4c82cd-lc.min.css | 69ms | 0ms | 0ms | 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/RC1608e7ad1cd541d690e9adec75ebc923-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://enelglobal.d3.sc.omtrdc.net/id?d_visid_ver=5.5.0&d_fieldgroup=A&mcorgid=374FFED355B616DC7F000101%40AdobeOrg&mid=68079291357984980824352322165135733313&ts=1783799902991 | 0 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://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 InventoryAction79 resources · 2.8 MB · 685 KB savings availableFIX
~684.7 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 79 resources | 2.8 MiB | ||||||
CImage OptimizationAction42 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
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
BJavaScript Blocking2 JS blocking issue(s) detectedREVIEW
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
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
A+CSS Performance DepthNo CSS performance depth issues 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 Waterfall79 requests over 3323msINFO
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 | 15306ms | 847 KB | 79% | €166/mo | Costly |
www.enel.com www.enel.com | Other | 7740ms | 51 KB | — | €84/mo | Costly |
assets.adobedtm.com assets.adobedtm.com | Other | 619ms | 92 KB | — | €7/mo | Costly |
consent.trustarc.com consent.trustarc.com | Other | 200ms | 31 KB | 71% | €2/mo | Costly |
consent.trustarc.com consent.trustarc.com | Other | 113ms | 13 KB | — | €1/mo | Optional |
www.enel.com www.enel.com | Other | 69ms | 137 KB | — | €1/mo | Optional |
These scripts may cost more than they're worth
- www.enel.com adds 15306ms and costs ~€166/month
- www.enel.com adds 7740ms and costs ~€84/month
- assets.adobedtm.com adds 619ms and costs ~€7/month
- consent.trustarc.com adds 200ms and costs ~€2/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 15306ms 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 7740ms 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 619ms 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
consent.trustarc.com takes 200ms 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