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.
2.26 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
3.39 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
30 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.027
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
2.26 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.
4.24 s
Page Load Progression
FPage Weight BudgetAction3.9 MB transferred, 89 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
Subset fonts to include only used characters, or switch to system font stacks.
Font payload is large — subset to used glyphs only, or fall back to system fonts (zero load time).
Source: web.dev font loading
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
DThird-Party ImpactAction100% third-party, 0 ms blockingFIX
DPage Weight InventoryAction89 resources · 3.9 MB · 161 KB savings availableFIX
~161.2 KiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 89 resources | 3.9 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
CImage OptimizationAction32 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
BJS Execution Cost770ms total JS executionREVIEW
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://www.biglobe.ne.jp/_astro/splidejsI18n.CngHA-3i.js | 239ms | 79ms | 0ms | 3rd |
| https://www.biglobe.ne.jp/ | 232ms | 4ms | 1ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-WHG7WT | 119ms | 99ms | 19ms | 3rd |
| Unattributable | 109ms | 3ms | 0ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-9EEHMB6SW3&cx=c>m=4e64h1 | 70ms | 57ms | 13ms | 3rd |
CJS BundlesAction16 scripts, 161 KB unusedREVIEW
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://www.googletagmanager.com/gtag/js?id=G-9EEHMB6SW3&cx=c>m=4e64h1 | 169 KB | 69 KB (40%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-WHG7WT | 201 KB | 65 KB (32%) | ✓ | 3rd |
| https://www.biglobe.ne.jp/_astro/runtime-core.esm-bundler.B648IbeZ.js | 62 KB | 28 KB (45%) | ✓ | 3rd |
| https://www.biglobe.ne.jp/_astro/index.astro_astro_type_script_index_2_lang.Bp20J1xI.js | 0 KB | — | ✓ | 3rd |
| https://d.adlpo.com/851/3010/js/smartadlpo_v3.js | 16 KB | — | ✓ | 3rd |
| https://www.biglobe.ne.jp/_astro/index.astro_astro_type_script_index_1_lang.ESkWpxB6.js | 0 KB | — | ✓ | 3rd |
| https://www.biglobe.ne.jp/_astro/SystemFailure.Dchck4SO.js | 7 KB | — | ✓ | 3rd |
| https://www.biglobe.ne.jp/_astro/client.DNnaKxFV.js | 7 KB | — | ✓ | 3rd |
| https://www.biglobe.ne.jp/_astro/splidejsI18n.CngHA-3i.js | 31 KB | — | ✓ | 3rd |
| https://www.biglobe.ne.jp/_astro/index.astro_astro_type_script_index_0_lang.zjG1D1Tg.js | 3 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
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 Loading30 fonts (627 KB)PASS
Web fonts
30
627 KB total
Render-blocking
0
of 30
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 Waterfall89 requests over 2450msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
www.biglobe.ne.jp www.biglobe.ne.jp | Other | 239ms | 31 KB | — | ¥331/mo | Costly |
www.biglobe.ne.jp www.biglobe.ne.jp | Other | 232ms | 176 KB | — | ¥321/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 119ms | 201 KB | 32% | ¥165/mo | Costly |
Unattributable Unattributable | Other | 109ms | 0 KB | — | ¥151/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 70ms | 169 KB | 40% | ¥97/mo | Costly |
These scripts may cost more than they're worth
- www.biglobe.ne.jp adds 239ms and costs ~¥331/month
- www.biglobe.ne.jp adds 232ms and costs ~¥321/month
- Google Tag Manager adds 119ms and costs ~¥165/month
- Unattributable adds 109ms and costs ~¥151/month
- Google Tag Manager adds 70ms and costs ~¥97/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.biglobe.ne.jp takes 239ms 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.biglobe.ne.jp takes 232ms 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 119ms 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 109ms 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 70ms 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