Performance
· 15 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.
998 ms
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
1.14 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
60 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.004
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
1.32 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.
2.05 s
Page Load Progression
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
DJS BundlesAction20 scripts, 398 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 | 103 KB (53%) | ✓ | 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? | 14 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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.wN2p-4XSz2TyAJlMxbFZA2chsNuIn-6AM_jdWnoetSg | 1 KB | — | ✓ | 3rd |
| https://www.lexology.com/js/react-bootstrap.js?v=eac4d250-ee6d-489f-a2ab-38fa67de113f | 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 InventoryAction69 resources · 1.6 MB · 398 KB savings availableFIX
~397.5 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 69 resources | 1.6 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CPage Weight BudgetAction1.6 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 OptimizationAction31 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
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
CJS Execution CostAction1098ms total JS executionREVIEW
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.lexology.com/ | 426ms | 13ms | 1ms | 3rd |
| Unattributable | 191ms | 31ms | 0ms | 3rd |
| https://lbr-embedded-lexology.lbr.cloud/static/js/lex-logged-out-homepage.d8850801.js | 167ms | 109ms | 22ms | 3rd |
| https://www.lexology.com/dist/react/static/js/sitewidev2.38b62aba.js | 119ms | 76ms | 29ms | 3rd |
| https://www.lexology.com/cdn-cgi/challenge-platform/scripts/jsd/main.js | 98ms | 86ms | 1ms | 3rd |
| https://cookie-cdn.cookiepro.com/scripttemplates/6.27.0/otBannerSdk.js | 98ms | 47ms | 8ms | 3rd |
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 HintsNo optimization neededPASS
A+Green HostingWhether the site is served from green-energy infrastructurePASS
Green Hosting
This site is hosted on green energy infrastructure
Provider: Cloudflare
Network Waterfall69 requests over 1825msINFO
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 | 426ms | 34 KB | — | €5/mo | Costly |
Unattributable Unattributable | Other | 191ms | 0 KB | — | €2/mo | Optional |
lbr-embedded-lexology.lbr.cloud lbr-embedded-lexology.lbr.cloud | Other | 167ms | 269 KB | 47% | €2/mo | Optional |
www.lexology.com www.lexology.com | Other | 119ms | 194 KB | 53% | €1/mo | Optional |
www.lexology.com www.lexology.com | Other | 98ms | 0 KB | — | €1/mo | Optional |
cookie-cdn.cookiepro.com cookie-cdn.cookiepro.com | Other | 98ms | 77 KB | 51% | €1/mo | Optional |
These scripts may cost more than they're worth
- www.lexology.com adds 426ms and costs ~€5/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 426ms 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.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
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