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.
1.50 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
4.22 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
621 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.010
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
3.86 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.
6.33 s
Page Load Progression
FPage Weight BudgetAction3.3 MB transferred, 200 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
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
DJS Execution CostAction2875ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://assets.babycenter.com/_next/static/chunks/framework-44b45b302b038cd6.js | 724ms | 545ms | 6ms | 3rd |
| Unattributable | 476ms | 20ms | 0ms | 3rd |
| https://www.babycenter.com/ | 271ms | 46ms | 2ms | 3rd |
| https://tagan.adlightning.com/babycenter/bl-682065e-dd34dc77.js | 248ms | 198ms | 10ms | 3rd |
| https://assets.babycenter.com/_next/static/chunks/pages/_app-96670ea9c301b279.js | 179ms | 129ms | 49ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-BP5N04S2Y3&cx=c>m=4e64h1 | 133ms | 111ms | 20ms | 3rd |
| https://securepubads.g.doubleclick.net/pagead/managed/js/gpt/m202604170101/pubads_impl.js?cb=31097963 | 118ms | 90ms | 19ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-PKLTNHJ>m_auth=>m_preview=>m_cookies_win=x | 107ms | 86ms | 17ms | 3rd |
| https://micro.rubiconproject.com/prebid/dynamic/13346.js | 104ms | 81ms | 22ms | 3rd |
| https://www.googletagmanager.com/gtag/destination?id=AW-1071964800&cx=c>m=4e64h1 | 91ms | 74ms | 15ms | 3rd |
Showing top 10 of 16 scripts
FJS BundlesAction86 scripts, 863 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://assets.babycenter.com/_next/static/chunks/pages/_app-96670ea9c301b279.js | 438 KB | 218 KB (50%) | ✓ | 3rd |
| https://securepubads.g.doubleclick.net/pagead/managed/js/gpt/m202604170101/pubads_impl.js?cb=31097963 | 187 KB | 124 KB (66%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-1071964800 | 145 KB | 106 KB (73%) | ✓ | 3rd |
| https://cdn.ziffstatic.com/jst/otBannerSdk.202512.1.0.js | 126 KB | 74 KB (59%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-BP5N04S2Y3&cx=c>m=4e64h1 | 164 KB | 66 KB (40%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/destination?id=AW-1071964800&cx=c>m=4e64h1 | 145 KB | 64 KB (44%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-PKLTNHJ>m_auth=>m_preview=>m_cookies_win=x | 160 KB | 63 KB (39%) | ✓ | 3rd |
| https://micro.rubiconproject.com/prebid/dynamic/13346.js | 168 KB | 49 KB (47%) | ✓ | 3rd |
| https://cdn.static.zdbb.net/js/z0WVjCBSEeGLoxIxOQVEwQ.min.js | 176 KB | 41 KB (23%) | ✓ | 3rd |
| https://fundingchoicesmessages.google.com/i/4213?ers=3 | 70 KB | 37 KB (54%) | ✓ | 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 InventoryAction200 resources · 3.3 MB · 863 KB savings availableFIX
~863.2 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 200 resources | 3.3 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CImage OptimizationAction59 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
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 Loading5 fonts (101 KB)PASS
Web fonts
5
101 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
Network Waterfall200 requests over 5537msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
assets.babycenter.com assets.babycenter.com | Other | 724ms | 57 KB | — | €8/mo | Costly |
Unattributable Unattributable | Other | 476ms | 0 KB | — | €5/mo | Costly |
www.babycenter.com www.babycenter.com | Other | 271ms | 136 KB | — | €3/mo | Costly |
tagan.adlightning.com tagan.adlightning.com | Other | 248ms | 102 KB | — | €3/mo | Costly |
assets.babycenter.com assets.babycenter.com | Other | 179ms | 438 KB | 50% | €2/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 133ms | 164 KB | 40% | €1/mo | Optional |
securepubads.g.doubleclick.net securepubads.g.doubleclick.net | Other | 118ms | 187 KB | 66% | €1/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 107ms | 160 KB | 39% | €1/mo | Optional |
micro.rubiconproject.com micro.rubiconproject.com | Other | 104ms | 168 KB | 47% | €1/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 91ms | 145 KB | 44% | €1/mo | Optional |
c.aps.amazon-adsystem.com c.aps.amazon-adsystem.com | Other | 90ms | 78 KB | — | €1/mo | Optional |
tagan.adlightning.com tagan.adlightning.com | Other | 80ms | 10 KB | — | €1/mo | Optional |
cdn.ziffstatic.com cdn.ziffstatic.com | Other | 73ms | 22 KB | — | €1/mo | Optional |
fundingchoicesmessages.google.com fundingchoicesmessages.google.com | Other | 67ms | 70 KB | 54% | €1/mo | Optional |
cdn.ziffstatic.com cdn.ziffstatic.com | Other | 64ms | 126 KB | 59% | €1/mo | Optional |
assets.babycenter.com assets.babycenter.com | Other | 51ms | 1 KB | — | €1/mo | Optional |
These scripts may cost more than they're worth
- assets.babycenter.com adds 724ms and costs ~€8/month
- Unattributable adds 476ms and costs ~€5/month
- www.babycenter.com adds 271ms and costs ~€3/month
- tagan.adlightning.com adds 248ms and costs ~€3/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
assets.babycenter.com takes 724ms 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 476ms 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.babycenter.com takes 271ms 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
tagan.adlightning.com takes 248ms 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
66% of securepubads.g.doubleclick.net'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
54% of fundingchoicesmessages.google.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
59% of cdn.ziffstatic.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