Performance
· 27 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.
3.43 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
9.24 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
644 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.000
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
7.50 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.
20.13 s
Page Load Progression
FPage Weight BudgetAction7.6 MB transferred, 270 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
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 ImpactAction70% third-party, 0 ms blockingFIX
FJS Execution CostAction9828ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://carrera-toys.com/de-eu | 5399ms | 580ms | 42ms | 1st |
| Unattributable | 1268ms | 49ms | 0ms | 3rd |
| https://consent.cookiebot.com/ce334302-3e60-47dd-9200-162f076aaa36/cc.js?renew=false&referer=carrera-toys.com&dnt=false&init=false | 468ms | 170ms | 23ms | 3rd |
| https://carrera-toys.com/cdn/shop/t/4/assets/theme.js?v=113927651260596923691776764253 | 430ms | 202ms | 13ms | 1st |
| https://widget.reviews.io/modern-widgets/ugc.js | 415ms | 338ms | 48ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-WK5NW5WC | 244ms | 203ms | 40ms | 3rd |
| https://cdn.jsdelivr.net/npm/swiper@11/swiper-bundle.min.js | 225ms | 26ms | 10ms | 3rd |
| https://static.klaviyo.com/onsite/js/1011.0ab7438f38097e529f79.js | 157ms | 84ms | 2ms | 3rd |
| https://ajax.googleapis.com/ajax/libs/jquery/3.7.1/jquery.min.js | 153ms | 24ms | 6ms | 3rd |
| https://static.klaviyo.com/onsite/js/build-preview/commit-b1cdef0395467d0ad1abcaf434a80c89dffcf374/sharedUtils.681e1664957bc982975a.js?cb=2 | 138ms | 59ms | 4ms | 3rd |
Showing top 10 of 21 scripts
FJS BundlesAction88 scripts, 396 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://widget.reviews.io/modern-widgets/ugc.js | 151 KB | 63 KB (43%) | ✓ | 3rd |
| https://cdn.shopify.com/extensions/019e07f9-107f-7e4e-9004-5549bb8fcd3c/swym-relay-739/assets/storefront-layout-components.js | 75 KB | 60 KB (80%) | ✗ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-WK5NW5WC | 175 KB | 58 KB (33%) | ✓ | 3rd |
| https://static.klaviyo.com/onsite/js/build-preview/commit-b1cdef0395467d0ad1abcaf434a80c89dffcf374/Render.01dba366182797ebdf1e.js | 53 KB | 41 KB (78%) | ✓ | 3rd |
| https://carrera-toys.com/cdn/wpm/b81a24193wb0bf602apf85b30fcm71c6b379m.js | 63 KB | 33 KB (53%) | ✓ | 1st |
| https://cdn.shopify.com/extensions/019d8b04-dc16-72dc-a957-0e51fcce6fee/transcy-ext-308/assets/transcy.js | 46 KB | 31 KB (70%) | ✓ | 3rd |
| https://carrera-toys.com/cdn/shop/t/4/assets/theme.js?v=113927651260596923691776764253 | 39 KB | 30 KB (80%) | ✓ | 1st |
| https://consent.cookiebot.eu/uc.js?cbid=ce334302-3e60-47dd-9200-162f076aaa36&implementation=gtm&consentmode-dataredaction=dynamic | 30 KB | 29 KB (98%) | ✓ | 3rd |
| https://consent.cookiebot.com/ce334302-3e60-47dd-9200-162f076aaa36/cc.js?renew=false&referer=carrera-toys.com&dnt=false&init=false | 114 KB | 26 KB (23%) | ✓ | 3rd |
| https://cdn.jsdelivr.net/npm/swiper@11/swiper-bundle.min.js | 43 KB | 25 KB (59%) | ✓ | 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 InventoryAction270 resources · 7.6 MB · 396 KB savings availableFIX
~396.3 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 270 resources | 7.6 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CImage OptimizationAction108 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
CCompression AlgorithmActionMain response served uncompressedREVIEW
BMain HTML Cache-ControlNo Cache-Control header on main HTML responseREVIEW
BJavaScript Blocking2 JS blocking issue(s) detectedREVIEW
A+Text CompressionAll text resources are compressedPASS
A+Font Loading3 fonts (35 KB)PASS
Web fonts
3
35 KB total
Render-blocking
0
of 3
Dominant font-display
swap
Most common across fonts
Font loading timeline
- Convert to woff2 for ~30% smaller file size
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
AResource Hints15 hints, 0 missing preconnectsPASS
Current Resource Hints
15 resource hints configured
preconnect already does the DNS lookup; adding dns-prefetch to the same origin is at best a no-op. Sample: https://procdn.swymrelay.com. Remove the redundant dns-prefetch entries.
Performance issues directly impact user engagement and conversion rates.
The same href shouldn't appear in multiple hint rels -- one wins, the others are wasted markup and may confuse cache behavior. Sample: //procdn.swymrelay.com/code/swym-shopify.js (preconnect+dns-prefetch).
Performance issues directly impact user engagement and conversion rates.
A+HTTP/3 (QUIC)HTTP/3 advertised via Alt-SvcPASS
A+LCP Image PreloadLCP preload audit not availablePASS
A+Server-Timing Observability14 Server-Timing entries advertisedPASS
A+Server Response Intelligence2 server-response signal(s) detectedPASS
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
ACSS Performance Depth1 CSS depth issue(s) 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 Waterfall270 requests over 6943msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
Unattributable Unattributable | Other | 1268ms | 0 KB | — | €7/mo | Costly |
consent.cookiebot.com consent.cookiebot.com | Other | 468ms | 114 KB | 23% | €2/mo | Costly |
widget.reviews.io widget.reviews.io | Other | 415ms | 151 KB | 43% | €2/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 244ms | 175 KB | 33% | €1/mo | Costly |
jsDelivr cdn.jsdelivr.net | CDN | 225ms | 43 KB | 59% | €1/mo | Costly |
static.klaviyo.com static.klaviyo.com | Other | 157ms | 8 KB | — | €1/mo | Optional |
ajax.googleapis.com ajax.googleapis.com | Other | 153ms | 30 KB | — | €1/mo | Optional |
static.klaviyo.com static.klaviyo.com | Other | 138ms | 23 KB | — | €1/mo | Optional |
static.klaviyo.com static.klaviyo.com | Other | 123ms | 53 KB | 78% | €1/mo | Optional |
consent.cookiebot.com consent.cookiebot.com | Other | 120ms | 27 KB | — | €1/mo | Optional |
cdn.shopify.com cdn.shopify.com | Other | 95ms | 75 KB | 80% | €0/mo | Optional |
cdn.shopify.com cdn.shopify.com | Other | 87ms | 46 KB | 70% | €0/mo | Optional |
cdn.shopify.com cdn.shopify.com | Other | 58ms | 15 KB | — | €0/mo | Optional |
These scripts may cost more than they're worth
- Unattributable adds 1268ms and costs ~€7/month
- consent.cookiebot.com adds 468ms and costs ~€2/month
- widget.reviews.io adds 415ms and costs ~€2/month
- Google Tag Manager adds 244ms and costs ~€1/month
- jsDelivr adds 225ms and costs ~€1/month
Unattributable takes 1268ms 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.cookiebot.com takes 468ms 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
widget.reviews.io takes 415ms 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 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
jsDelivr takes 225ms 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 jsDelivr'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
78% of static.klaviyo.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
80% of cdn.shopify.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
70% of cdn.shopify.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
Real-User Performance (CrUX)Field metrics from the Chrome User Experience ReportINFO
Chrome User Experience (CrUX)
Real-user metrics from the Chrome UX Report (2026-04-11 — 2026-05-08)
LCP (p75)
1781 ms
86% good
INP (p75)
135 ms
88% good
CLS (p75)
0.000
83% good
FCP (p75)
1366 ms
TTFB (p75)
619 ms
Image Optimization200 images, 277 KB total, 88 KB wastedINFO
Image Optimization Audit
Total Images
200
Total Size
277 KB
Oversized
25
Wasted
88 KB