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.
1.08 s
Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.
2.61 s
Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.
401 ms
Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.
0.005
Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.
2.94 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.
5.74 s
Page Load Progression
FPage Weight BudgetAction16.7 MB transferred, 134 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 CostAction3510ms total JS executionFIX
Main Thread Breakdown
| Script | Total | Scripting | Parse/Compile | Party |
|---|---|---|---|---|
| https://t.contentsquare.net/uxa/12bfe507f39ec.js | 893ms | 810ms | 17ms | 3rd |
| https://www.softbank.jp/ | 811ms | 2ms | 1ms | 3rd |
| https://www.softbank.jp/site/set/data/top/js/p/2026/index.js | 573ms | 204ms | 5ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-BMSW | 345ms | 282ms | 22ms | 3rd |
| Unattributable | 279ms | 21ms | 0ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-MRJVDLW7>m=4e64h1 | 106ms | 56ms | 19ms | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-4MD1NXTN7F&cx=c>m=4e64h1 | 85ms | 71ms | 14ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-W6RH4KH>m=4e64h1 | 85ms | 61ms | 22ms | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-P8N6VWTZ>m=4e64h1 | 76ms | 55ms | 20ms | 3rd |
| https://cdn.eu.heap-api.com/v5/heapjs-static/5.3.12/core/heap.js | 75ms | 64ms | 10ms | 3rd |
Showing top 10 of 13 scripts
FJS BundlesAction27 scripts, 1.0 MB unusedFIX
Downloaded but never executed on this page.
| Script | Size | Unused | Minified | Party |
|---|---|---|---|---|
| https://creativesurvey-ent-prod-upload-contents.s3.amazonaws.com/uploads/production/survin/script/23/survin.js | 625 KB | 332 KB (53%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-TNDFTGNX>m=4e64h1 | 173 KB | 73 KB (42%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-54HJTVSQ>m=4e64h1 | 172 KB | 71 KB (41%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-P8N6VWTZ>m=4e64h1 | 175 KB | 69 KB (39%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-MPWDW7WF>m=4e64h1 | 116 KB | 69 KB (59%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-MRJVDLW7>m=4e64h1 | 169 KB | 67 KB (40%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtag/js?id=G-4MD1NXTN7F&cx=c>m=4e64h1 | 154 KB | 64 KB (41%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-BMSW | 191 KB | 60 KB (31%) | ✓ | 3rd |
| https://t.contentsquare.net/uxa/12bfe507f39ec.js | 152 KB | 57 KB (49%) | ✓ | 3rd |
| https://www.googletagmanager.com/gtm.js?id=GTM-W6RH4KH>m=4e64h1 | 128 KB | 56 KB (44%) | ✓ | 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
FPage Weight InventoryAction134 resources · 16.7 MB · 1.0 MB savings availableFIX
~1.0 MiB of savings available
| # | Resource | Type | Size | Cache | Unused | 3rd party | Issues |
|---|---|---|---|---|---|---|---|
| — | — | ||||||
| 134 resources | 16.7 MiB | ||||||
FHTTP CachingActionNo cache headersFIX
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
BImage Optimization71 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
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 HintsNo optimization neededPASS
Network Waterfall134 requests over 4813msINFO
Third-Party Script CostPer-script blocking time, transfer cost, and cache headersINFO
| Script | Category | Execution | Transfer | Unused | Monthly Cost | Verdict |
|---|---|---|---|---|---|---|
t.contentsquare.net t.contentsquare.net | Other | 893ms | 152 KB | 49% | ¥5/mo | Costly |
www.softbank.jp www.softbank.jp | Other | 811ms | 10 KB | — | ¥5/mo | Costly |
www.softbank.jp www.softbank.jp | Other | 573ms | 65 KB | 44% | ¥3/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 345ms | 191 KB | 31% | ¥2/mo | Costly |
Unattributable Unattributable | Other | 279ms | 0 KB | — | ¥2/mo | Costly |
Google Tag Manager www.googletagmanager.com | Tag Manager | 106ms | 169 KB | 40% | ¥1/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 85ms | 154 KB | 41% | ¥0/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 85ms | 128 KB | 44% | ¥0/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 76ms | 175 KB | 39% | ¥0/mo | Optional |
cdn.eu.heap-api.com cdn.eu.heap-api.com | Other | 75ms | 75 KB | 39% | ¥0/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 63ms | 172 KB | 41% | ¥0/mo | Optional |
creativesurvey-ent-prod-upload-contents.s3.amazonaws.com creativesurvey-ent-prod-upload-contents.s3.amazonaws.com | Other | 61ms | 625 KB | 53% | ¥0/mo | Optional |
Google Tag Manager www.googletagmanager.com | Tag Manager | 59ms | 173 KB | 42% | ¥0/mo | Optional |
These scripts may cost more than they're worth
- t.contentsquare.net adds 893ms and costs ~¥5/month
- www.softbank.jp adds 811ms and costs ~¥5/month
- www.softbank.jp adds 573ms and costs ~¥3/month
- Google Tag Manager adds 345ms and costs ~¥2/month
- Unattributable adds 279ms and costs ~¥2/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
t.contentsquare.net takes 893ms 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.softbank.jp takes 811ms 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.softbank.jp takes 573ms 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 345ms 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 279ms 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 creativesurvey-ent-prod-upload-contents.s3.amazonaws.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