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.
3.64 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
5.20 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
5.13 s
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.002
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
10.02 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.
29.51 s
Page Load Progression
FPage Weight BudgetAction3.6 MB transferred, 193 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
FJS Execution CostAction11793ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://assets.babycenter.com/_next/static/chunks/framework-44b45b302b038cd6.js | 2943ms | 2187ms | 25ms | 3rd |
| Unattributable | 1555ms | 65ms | 0ms | 3rd |
| https://www.babycenter.com/ | 1027ms | 170ms | 10ms | 3rd |
| https://tagan.adlightning.com/babycenter/bl-682065e-dd34dc77.js | 869ms | 714ms | 37ms | 3rd |
| https://assets.babycenter.com/_next/static/chunks/pages/_app-96670ea9c301b279.js | 747ms | 549ms | 192ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-PKLTNHJ>m_auth=>m_preview=>m_cookies_win=x | 467ms | 364ms | 69ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-BP5N04S2Y3&cx=c>m=4e64h1 | 427ms | 354ms | 64ms | 3rd |
| https://securepubads.g.doubleclick.net/pagead/managed/js/gpt/m202604160201/pubads_impl.js | 379ms | 283ms | 80ms | 3rd |
| https://micro.rubiconproject.com/prebid/dynamic/13346.js | 374ms | 282ms | 88ms | 3rd |
| https://www.googletagmanager.com/gtag/destination?id=AW-1071964800&cx=c>m=4e64h1 | 334ms | 267ms | 60ms | 3rd |
Showing top 10 of 26 scripts
FJS BundlesAction86 scripts, 1.1 MB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://securepubads.g.doubleclick.net/pagead/managed/js/gpt/m202604160201/pubads_impl.js | 600 KB | 401 KB (67%) | ✓ | 3rd |
| https://assets.babycenter.com/_next/static/chunks/pages/_app-96670ea9c301b279.js | 438 KB | 219 KB (50%) | ✓ | 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 | 174 KB | 59 KB (50%) | ✓ | 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 InventoryAction193 resources · 3.6 MB · 1.1 MB savings availableFIX
~1.1 MiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 193 resources | 3.6 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CImage OptimizationAction52 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
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 Hints32 hints, 0 missing preconnectsPASS
Current Resource Hints
32 resource hints configured
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
Network Waterfall193 requests over 5187msINFO
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 | 2943ms | 57 KB | — | €32/mo | Costly |
Unattributable Unattributable | Other | 1555ms | 0 KB | — | €17/mo | Costly |
www.babycenter.com www.babycenter.com | Other | 1027ms | 136 KB | — | €11/mo | Costly |
tagan.adlightning.com tagan.adlightning.com | Other | 869ms | 102 KB | — | €9/mo | Costly |
assets.babycenter.com assets.babycenter.com | Other | 747ms | 438 KB | 50% | €8/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 467ms | 160 KB | 39% | €5/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 427ms | 164 KB | 40% | €5/mo | Costly |
securepubads.g.doubleclick.net securepubads.g.doubleclick.net | Other | 379ms | 600 KB | 67% | €4/mo | Costly |
micro.rubiconproject.com micro.rubiconproject.com | Other | 374ms | 174 KB | 50% | €4/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 334ms | 145 KB | 44% | €4/mo | Costly |
tagan.adlightning.com tagan.adlightning.com | Other | 286ms | 10 KB | — | €3/mo | Costly |
cdn.ziffstatic.com cdn.ziffstatic.com | Other | 282ms | 22 KB | — | €3/mo | Costly |
c.aps.amazon-adsystem.com c.aps.amazon-adsystem.com | Other | 257ms | 78 KB | — | €3/mo | Costly |
fundingchoicesmessages.google.com fundingchoicesmessages.google.com | Other | 255ms | 70 KB | 54% | €3/mo | Costly |
cdn.ziffstatic.com cdn.ziffstatic.com | Other | 244ms | 126 KB | 59% | €3/mo | Costly |
tagan.adlightning.com tagan.adlightning.com | Other | 165ms | 34 KB | 65% | €2/mo | Optional |
securepubads.g.doubleclick.net securepubads.g.doubleclick.net | Other | 153ms | 34 KB | — | €2/mo | Optional |
assets.babycenter.com assets.babycenter.com | Other | 150ms | 1 KB | — | €2/mo | Optional |
assets.babycenter.com assets.babycenter.com | Other | 150ms | 42 KB | — | €2/mo | Optional |
cdn.static.zdbb.net cdn.static.zdbb.net | Other | 137ms | 176 KB | 23% | €1/mo | Optional |
cdn.ziffstatic.com cdn.ziffstatic.com | Other | 129ms | 28 KB | — | €1/mo | Optional |
pub.doubleverify.com pub.doubleverify.com | Other | 128ms | 19 KB | — | €1/mo | Optional |
assets.babycenter.com assets.babycenter.com | Other | 97ms | 21 KB | — | €1/mo | Optional |
www.babycenter.com www.babycenter.com | Other | 93ms | 25 KB | — | €1/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 89ms | 145 KB | 73% | €1/mo | Optional |
Bing UET bat.bing.com | Advertising | 55ms | 16 KB | — | €1/mo | Optional |
These scripts may cost more than they're worth
- assets.babycenter.com adds 2943ms and costs ~€32/month
- Unattributable adds 1555ms and costs ~€17/month
- www.babycenter.com adds 1027ms and costs ~€11/month
- tagan.adlightning.com adds 869ms and costs ~€9/month
- assets.babycenter.com adds 747ms and costs ~€8/month
- Google Tag Manager adds 467ms and costs ~€5/month
- Google Tag Manager adds 427ms and costs ~€5/month
- securepubads.g.doubleclick.net adds 379ms and costs ~€4/month
- micro.rubiconproject.com adds 374ms and costs ~€4/month
- Google Tag Manager adds 334ms and costs ~€4/month
- tagan.adlightning.com adds 286ms and costs ~€3/month
- cdn.ziffstatic.com adds 282ms and costs ~€3/month
- c.aps.amazon-adsystem.com adds 257ms and costs ~€3/month
- fundingchoicesmessages.google.com adds 255ms and costs ~€3/month
- cdn.ziffstatic.com adds 244ms 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 2943ms 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 1555ms 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 1027ms 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 869ms 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.babycenter.com takes 747ms 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
50% of assets.babycenter.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 467ms 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
Google Tag Manager takes 427ms 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
securepubads.g.doubleclick.net takes 379ms 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
67% 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
micro.rubiconproject.com takes 374ms 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
50% of micro.rubiconproject.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 334ms 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 286ms 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
cdn.ziffstatic.com takes 282ms 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
c.aps.amazon-adsystem.com takes 257ms 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
fundingchoicesmessages.google.com takes 255ms 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
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
cdn.ziffstatic.com takes 244ms 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
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
65% of tagan.adlightning.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
73% 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