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.
2.47 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
4.29 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
8 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.847
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
2.47 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.
4.31 s
Page Load Progression
375 ms 750 ms
1.1 s
1.5 s
1.9 s 2.2 s 2.6 s
3.0 sFPage Weight BudgetAction6.6 MB transferred, 113 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 ImpactAction100% third-party, 0 ms blockingFIX
DPage Weight InventoryAction113 resources · 6.6 MB · 97 KB savings availableFIX
~96.7 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 113 resources | 6.6 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CImage OptimizationAction27 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
CJS Execution CostAction1005ms total JS executionREVIEW
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.nintendo.com/es-es/ | 559ms | 89ms | 0ms | 3rd |
| Unattributable | 379ms | 177ms | 0ms | 3rd |
| https://cdn.cookielaw.org/scripttemplates/202503.1.0/otBannerSdk.js | 67ms | 44ms | 9ms | 3rd |
BJS Bundles52 scripts, 97 KB unusedREVIEW
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://cdn.cookielaw.org/scripttemplates/202503.1.0/otBannerSdk.js | 116 KB | 61 KB (53%) | ✓ | 3rd |
| https://www.nintendo.com/eu/app_static/assets/CqnbhlbB.js | 123 KB | 35 KB (42%) | ✓ | 3rd |
| https://alps.cdn.nintendo.net/v1/js/account_es_EUR.js | 37 KB | — | ✓ | 3rd |
| https://cdn.cookielaw.org/scripttemplates/otSDKStub.js | 9 KB | — | ✓ | 3rd |
| https://www.nintendo.com/eu/app_static/assets/CPWWdYs0.js | 5 KB | — | ✓ | 3rd |
| https://www.nintendo.com/eu/app_static/assets/DIMaRtX9.js | 1 KB | — | ✓ | 3rd |
| https://www.nintendo.com/eu/app_static/assets/BCqGhHQZ.js | 11 KB | — | ✓ | 3rd |
| https://www.nintendo.com/eu/app_static/assets/BLhGjMxX.js | 2 KB | — | ✓ | 3rd |
| https://www.nintendo.com/eu/app_static/assets/jE0zBmnv.js | 647 KB | — | ✓ | 3rd |
| https://www.nintendo.com/eu/app_static/assets/CobVX0U6.js | 2 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
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 Loading4 fonts (124 KB)PASS
Web fonts
4
124 KB total
Render-blocking
0
of 4
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 Waterfall113 requests over 2185msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.nintendo.com www.nintendo.com | Other | 559ms | 824 KB | — | $7/mo | Costly |
Unattributable Unattributable | Other | 379ms | 0 KB | — | $5/mo | Costly |
OneTrust cdn.cookielaw.org | Consent | 67ms | 116 KB | 53% | $1/mo | Essential |
These scripts may cost more than they're worth
- www.nintendo.com adds 559ms and costs ~$7/month
- Unattributable adds 379ms 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.nintendo.com takes 559ms 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 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
53% of OneTrust'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