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.
6.30 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
9.72 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
598 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.038
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
6.98 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.
9.96 s
Page Load Progression
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
FJS Execution CostAction4608ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.lexology.com/ | 1412ms | 57ms | 4ms | 3rd |
| https://lbr-embedded-lexology.lbr.cloud/static/js/lex-logged-out-homepage.d8850801.js | 698ms | 439ms | 90ms | 3rd |
| Unattributable | 633ms | 77ms | 0ms | 3rd |
| https://www.lexology.com/cdn-cgi/challenge-platform/scripts/jsd/main.js | 503ms | 353ms | 3ms | 3rd |
| https://www.lexology.com/dist/react/static/js/sitewidev2.38b62aba.js | 490ms | 369ms | 99ms | 3rd |
| https://cookie-cdn.cookiepro.com/scripttemplates/6.27.0/otBannerSdk.js | 399ms | 198ms | 37ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-TPRFN09B8E | 212ms | 114ms | 55ms | 3rd |
| https://cookie-cdn.cookiepro.com/scripttemplates/otSDKStub.js | 180ms | 160ms | 3ms | 3rd |
| https://lbr-embedded-lexology.lbr.cloud/static/js/886.a3470183.chunk.js | 81ms | 66ms | 15ms | 3rd |
DJS BundlesAction20 scripts, 395 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://lbr-embedded-lexology.lbr.cloud/static/js/lex-logged-out-homepage.d8850801.js | 269 KB | 127 KB (47%) | ✓ | 3rd |
| https://www.lexology.com/dist/react/static/js/sitewidev2.38b62aba.js | 194 KB | 100 KB (52%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-TPRFN09B8E | 177 KB | 94 KB (53%) | ✓ | 3rd |
| https://cookie-cdn.cookiepro.com/scripttemplates/6.27.0/otBannerSdk.js | 77 KB | 39 KB (51%) | ✓ | 3rd |
| https://lbr-embedded-lexology.lbr.cloud/static/js/886.a3470183.chunk.js | 44 KB | 35 KB (80%) | ✓ | 3rd |
| https://cookie-cdn.cookiepro.com/consent/930d40f3-7bc1-4bec-938c-9c8ed3e61516/4e78fb58-b179-40e8-923b-2781c0efb7ac/en.json | 11 KB | — | ✓ | 3rd |
| https://www.lexology.com/cdn-cgi/challenge-platform/h/b/scripts/jsd/0b8fb825cb67/main.js? | 13 KB | — | ✓ | 3rd |
| https://cookie-cdn.cookiepro.com/scripttemplates/otSDKStub.js | 9 KB | — | ✓ | 3rd |
| https://lbr-embedded-lexology.lbr.cloud/embeddedapp/lex-logged-out-homepage?tk=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.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.mOk8U2n2CObtQFdGsYg6Loi6_z-RgDk0ors7Xy6ezFg | 1 KB | — | ✓ | 3rd |
| https://www.lexology.com/js/react-bootstrap.js?v=f58f0870-19e9-4020-904a-e957e322a4ad | 1 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
DPage Weight InventoryAction63 resources · 1.5 MB · 395 KB savings availableFIX
~394.6 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 63 resources | 1.5 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
BPage Weight Budget1.5 MB transferred, 63 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 OptimizationAction25 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
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
A+Text CompressionAll text resources are compressedPASS
A+Font Loading1 fonts (37 KB)PASS
Web fonts
1
37 KB total
Render-blocking
0
of 1
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 Hints10 hints, 0 missing preconnectsPASS
Current Resource Hints
10 resource hints configured
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources 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 Waterfall63 requests over 2586msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.lexology.com www.lexology.com | Other | 1412ms | 34 KB | — | €15/mo | Costly |
lbr-embedded-lexology.lbr.cloud lbr-embedded-lexology.lbr.cloud | Other | 698ms | 269 KB | 47% | €8/mo | Costly |
Unattributable Unattributable | Other | 633ms | 0 KB | — | €7/mo | Costly |
www.lexology.com www.lexology.com | Other | 503ms | 0 KB | — | €5/mo | Costly |
www.lexology.com www.lexology.com | Other | 490ms | 194 KB | 52% | €5/mo | Costly |
cookie-cdn.cookiepro.com cookie-cdn.cookiepro.com | Other | 399ms | 77 KB | 51% | €4/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 212ms | 177 KB | 53% | €2/mo | Costly |
cookie-cdn.cookiepro.com cookie-cdn.cookiepro.com | Other | 180ms | 9 KB | — | €2/mo | Optional |
lbr-embedded-lexology.lbr.cloud lbr-embedded-lexology.lbr.cloud | Other | 81ms | 44 KB | 80% | €1/mo | Optional |
These scripts may cost more than they're worth
- www.lexology.com adds 1412ms and costs ~€15/month
- lbr-embedded-lexology.lbr.cloud adds 698ms and costs ~€8/month
- Unattributable adds 633ms and costs ~€7/month
- www.lexology.com adds 503ms and costs ~€5/month
- www.lexology.com adds 490ms and costs ~€5/month
- cookie-cdn.cookiepro.com adds 399ms and costs ~€4/month
- Google Tag Manager adds 212ms and costs ~€2/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
www.lexology.com takes 1412ms 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
lbr-embedded-lexology.lbr.cloud takes 698ms 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 633ms 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.lexology.com takes 503ms 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.lexology.com takes 490ms 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
52% of www.lexology.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
cookie-cdn.cookiepro.com takes 399ms 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
51% of cookie-cdn.cookiepro.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 212ms 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 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
80% of lbr-embedded-lexology.lbr.cloud'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