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.
3.00 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
7.11 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
745 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.014
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
8.90 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.
12.71 s
Page Load Progression
FPage Weight BudgetAction2.6 MB transferred, 144 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
FJS Execution CostAction5428ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.nikkei.com/ | 2170ms | 21ms | 4ms | 3rd |
| Unattributable | 1102ms | 37ms | 0ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-PXS8451SBG | 620ms | 497ms | 69ms | 3rd |
| https://www.nikkei.com/.resources/k2-top/main.rev-727ad7f4.js | 454ms | 414ms | 9ms | 3rd |
| https://www.nikkei.com/.resources/tracking/static/atlas/atj.min.rev-c6c444.js | 370ms | 126ms | 3ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=AW-1024704716&cx=c>m=4e64e1h1&bs=ctrl2 | 321ms | 260ms | 52ms | 3rd |
| https://connect.facebook.net/signals/config/517132292271830?v=2.9.298&r=stable&domain=www.nikkei.com&hme=c048e760b3fdc0fbdc117d7607b2c36e13eff2660c515ac72e86dac5ba060bb9&ex_m=104%2C205%2C154%2C22%2C72%2C73%2C145%2C68%2C67%2C11%2C162%2C90%2C16%2C138%2C127%2C39%2C75%2C78%2C134%2C159%2C164%2C8%2C4%2C5%2C7%2C6%2C3%2C91%2C101%2C165%2C170%2C219%2C62%2C186%2C187%2C55%2C277%2C30%2C74%2C231%2C230%2C229%2C23%2C33%2C103%2C61%2C10%2C63%2C97%2C98%2C99%2C105%2C130%2C31%2C29%2C132%2C133%2C129%2C128%2C155%2C76%2C158%2C156%2C157%2C50%2C60%2C123%2C15%2C161%2C45%2C264%2C265%2C263%2C26%2C27%2C28%2C48%2C146%2C77%2C112%2C18%2C20%2C44%2C40%2C42%2C41%2C83%2C92%2C96%2C110%2C144%2C147%2C46%2C111%2C24%2C21%2C119%2C69%2C36%2C149%2C148%2C150%2C141%2C139%2C25%2C35%2C59%2C109%2C160%2C70%2C17%2C152%2C114%2C81%2C66%2C19%2C85%2C86%2C116%2C84%2C136%2C135%2C34%2C279%2C294%2C212%2C201%2C202%2C200%2C297%2C289%2C52%2C213%2C107%2C131%2C80%2C121%2C54%2C47%2C49%2C113%2C120%2C126%2C58%2C64%2C151%2C115%2C37%2C32%2C53%2C56%2C100%2C163%2C1%2C124%2C14%2C122%2C12%2C2%2C57%2C93%2C65%2C118%2C89%2C88%2C166%2C167%2C94%2C95%2C9%2C125%2C102%2C51%2C142%2C87%2C79%2C71%2C117%2C106%2C43%2C143%2C0%2C82%2C137%2C140%2C153%2C38%2C108%2C13%2C168 | 171ms | 145ms | 24ms | 3rd |
| https://connect.facebook.net/en_US/fbevents.js | 164ms | 119ms | 44ms | 3rd |
| https://www.nikkei.com/.resources/k-components/rtoaster/view.rev-e54ba78.html?data=eyJlbGVtZW50SWQiOiJyY21kX2tpdGVfbm90aWZpY2F0aW9uIn0%3D&pageUrl=https%3A%2F%2Fwww.nikkei.com%2F | 56ms | 31ms | 3ms | 3rd |
DPage Weight InventoryAction144 resources · 2.6 MB · 183 KB savings availableFIX
~182.6 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 144 resources | 2.6 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CImage OptimizationAction93 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
CJS BundlesAction23 scripts, 183 KB unusedREVIEW
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.googletagmanager.com/gtag/js?id=AW-1024704716&cx=c>m=4e64e1h1&bs=ctrl2 | 144 KB | 55 KB (38%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-PXS8451SBG | 174 KB | 55 KB (32%) | ✓ | 3rd |
| https://www.nikkei.com/.resources/k2-top/main.rev-727ad7f4.js | 134 KB | 40 KB (38%) | ✓ | 3rd |
| https://connect.facebook.net/en_US/fbevents.js | 96 KB | 32 KB (34%) | ✓ | 3rd |
| https://nkispa.nikkei.com/fh/showad_d094700e_d.js | 2 KB | — | ✓ | 3rd |
| https://partsa.nikkei.com/static/nkis/js/foneH.js | 3 KB | — | ✓ | 3rd |
| https://www.nikkei.com/.resources/tracking/static/atlas/atj.min.rev-c6c444.js | 7 KB | — | ✓ | 3rd |
| https://www.nikkei.com/.resources/tracking/static/atlas/c2p.rev-8c9198.js | 2 KB | — | ✓ | 3rd |
| https://www.nikkei.com/.resources/tracking/static/atlas/link-tracking.rev-c01db9.js | 1 KB | — | ✓ | 3rd |
| https://www.nikkei.com/.resources/tracking/static/atlas/google-analytics.rev-896d69.js | 1 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
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 LoadingNo web fonts (system fonts)PASS
A+Resource CachingAll resources properly cachedPASS
A+Critical Rendering PathNo render-blocking resourcesPASS
A+Resource Hints19 hints, 0 missing preconnectsPASS
Current Resource Hints
19 resource hints configured
A+Render-Blocking ResourcesNo render-blocking resources detectedPASS
A+Third-Party ResourcesNo third-party resources detectedPASS
Network Waterfall144 requests over 7062msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.nikkei.com www.nikkei.com | Other | 2170ms | 71 KB | — | ¥2998/mo | Costly |
Unattributable Unattributable | Other | 1102ms | 0 KB | — | ¥1522/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 620ms | 174 KB | 32% | ¥857/mo | Costly |
www.nikkei.com www.nikkei.com | Other | 454ms | 134 KB | 38% | ¥627/mo | Costly |
www.nikkei.com www.nikkei.com | Other | 370ms | 7 KB | — | ¥512/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 321ms | 144 KB | 38% | ¥444/mo | Costly |
Facebook Pixel connect.facebook.net | Advertising | 171ms | 44 KB | — | ¥236/mo | Costly |
Facebook Pixel connect.facebook.net | Advertising | 164ms | 96 KB | 34% | ¥227/mo | Costly |
www.nikkei.com www.nikkei.com | Other | 56ms | 18 KB | — | ¥77/mo | Costly |
These scripts may cost more than they're worth
- www.nikkei.com adds 2170ms and costs ~¥2998/month
- Unattributable adds 1102ms and costs ~¥1522/month
- Google Tag Manager adds 620ms and costs ~¥857/month
- www.nikkei.com adds 454ms and costs ~¥627/month
- www.nikkei.com adds 370ms and costs ~¥512/month
- Google Tag Manager adds 321ms and costs ~¥444/month
- Facebook Pixel adds 171ms and costs ~¥236/month
- Facebook Pixel adds 164ms and costs ~¥227/month
- www.nikkei.com adds 56ms and costs ~¥77/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.nikkei.com takes 2170ms 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 1102ms 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 620ms 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.nikkei.com takes 454ms 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.nikkei.com takes 370ms 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 321ms 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
Facebook Pixel takes 171ms 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
Facebook Pixel takes 164ms 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.nikkei.com takes 56ms 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