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.
4.61 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
22.61 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
1.49 s
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.
9.27 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.
22.84 s
Page Load Progression
FPage Weight BudgetAction4.1 MB transferred, 176 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
FJS Execution CostAction4822ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| Unattributable | 894ms | 18ms | 0ms | 1st |
| https://rentcoolcubes.com/ | 732ms | 124ms | 24ms | 1st |
| https://js.hs-analytics.net/analytics/1785157200000/43642784.js | 643ms | 481ms | 12ms | 3rd |
| https://rentcoolcubes.com/cdn/shop/t/14/assets/theme.js?v=140924482945350573091746543398 | 497ms | 49ms | 24ms | 1st |
| https://www.googletagmanager.com/gtag/js?id=G-DE42LVPV79 | 407ms | 360ms | 42ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-17615131819 | 334ms | 294ms | 38ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-DE42LPVV79&cx=c>m=4e67m0 | 208ms | 172ms | 34ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-NZB5Q3Q6 | 189ms | 147ms | 41ms | 3rd |
| https://rentcoolcubes.com/cdn/s/trekkie.storefront.51e77662fd67e0d47c7238acfeab529dafb90214.min.js | 161ms | 122ms | 37ms | 1st |
| https://rentcoolcubes.com/cdn/wpm/b0b92dcedw658847c9p94194e39m8bc44e9fm.js | 132ms | 108ms | 23ms | 1st |
Showing top 10 of 18 scripts
FJS BundlesAction110 scripts, 532 KB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.googletagmanager.com/gtag/js?id=G-DE42LVPV79&cx=c>m=4e67m0 | 180 KB | 119 KB (66%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-NZB5Q3Q6 | 151 KB | 85 KB (56%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-DE42LPVV79&cx=c>m=4e67m0 | 145 KB | 69 KB (48%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-DE42LVPV79 | 180 KB | 66 KB (37%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-17615131819 | 153 KB | 60 KB (39%) | ✓ | 3rd |
| https://cdn.jsdelivr.net/npm/swiper@11/swiper-bundle.min.js | 43 KB | 42 KB (97%) | ✓ | 3rd |
| https://rentcoolcubes.com/cdn/wpm/b0b92dcedw658847c9p94194e39m8bc44e9fm.js | 68 KB | 35 KB (53%) | ✓ | 1st |
| https://rentcoolcubes.com/cdn/shop/t/14/assets/vendor-scripts-v14.js | 37 KB | 29 KB (79%) | ✓ | 1st |
| https://rentcoolcubes.com/cdn/shop/t/14/assets/theme.js?v=140924482945350573091746543398 | 35 KB | 27 KB (78%) | ✓ | 1st |
| https://rentcoolcubes.com/cdn/shopifycloud/checkout-web/assets/c1/context-browser.vhmrDEZK.js | 65 KB | — | ✓ | 1st |
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 InventoryAction176 resources · 4.1 MB · 532 KB savings availableFIX
~532.3 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 176 resources | 4.1 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CImage OptimizationAction20 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
BMain HTML Cache-ControlNo Cache-Control header on main HTML responseREVIEW
AThird-Party Impact28% third-party, 0 ms blockingPASS
A+Text CompressionAll text resources are compressedPASS
A+Font LoadingNo web fonts (system fonts)PASS
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+HTTP/3 (QUIC)HTTP/3 advertised via Alt-SvcPASS
A+Compression AlgorithmMain response uses brotliPASS
A+LCP Image PreloadLCP preload audit not availablePASS
A+Server-Timing Observability1 Server-Timing entries advertisedPASS
AServer Response Intelligence2 server-response signal(s) detectedPASS
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
AJavaScript Blocking1 JS blocking issue(s) 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 Waterfall176 requests over 4763msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
HubSpot Analytics js.hs-analytics.net | Analytics | 643ms | 43 KB | — | €3/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 407ms | 180 KB | 37% | €2/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 334ms | 153 KB | 39% | €2/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 208ms | 145 KB | 48% | €1/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 189ms | 151 KB | 56% | €1/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 99ms | 180 KB | 66% | €1/mo | Optional |
js.hscollectedforms.net js.hscollectedforms.net | Other | 90ms | 27 KB | — | €0/mo | Optional |
js.hsforms.net js.hsforms.net | Other | 55ms | 16 KB | — | €0/mo | Optional |
www.gstatic.com www.gstatic.com | Other | 52ms | 20 KB | — | €0/mo | Optional |
These scripts may cost more than they're worth
- HubSpot Analytics adds 643ms and costs ~€3/month
- Google Tag Manager adds 407ms and costs ~€2/month
- Google Tag Manager adds 334ms and costs ~€2/month
- Google Tag Manager adds 208ms and costs ~€1/month
43% of JavaScript execution time comes from third-party scripts.
Third-party scripts (analytics, ads, social, A/B testing) often dominate execution time — every one is a perf-and-privacy tax.
Learn more ▾ ▴
Each third-party script is a black box: you don't control when it loads, what it executes, or how much it grows. They often account for a major share of total blocking time on average sites (HTTP Archive's Web Almanac documents the trend). Audit which ones you actually need, defer the rest, and use facade patterns (lite-youtube, lite-vimeo) for embedded media.
Source: web.dev / HTTP Archive Web Almanac
HubSpot Analytics takes 643ms 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 407ms 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 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
Google Tag Manager takes 208ms 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
56% 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
66% 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
Real-User Performance (CrUX)Field metrics from the Chrome User Experience ReportINFO
Chrome User Experience (CrUX)
Real-user metrics from the Chrome UX Report (2026-06-28 — 2026-07-25)
LCP (p75)
0 ms
0% good
INP (p75)
0 ms
0% good
CLS (p75)
0.000
99% good
FCP (p75)
2711 ms
TTFB (p75)
697 ms
Image Optimization39 images, 6484 KB total, 1483 KB wastedINFO
Image Optimization Audit
Total Images
39
Total Size
6484 KB
Oversized
5
Wasted
1483 KB