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https://www.asahi.com

Performance

· 14 checks — Lighthouse + waterfall + sustainability rolled into one auditable list.
SCORE
70
GRADE
C
FIX
4
REVIEW
3
PASS
5
INFO
2

Performance-focused optimization plan with CWV assessment, top offenders, and time estimates

Mobile Desktop
56
Performance Overall performance score (0–100) based on Core Web Vitals and other metrics. 90+ is good.
92
Accessibility Measures how accessible the page is for users with disabilities. Checks color contrast, ARIA labels, and semantic HTML.
69
Best Practices Checks for modern web development best practices including HTTPS, no console errors, and secure JavaScript.
85
SEO Measures basic SEO optimizations: meta tags, crawlability, link text, and mobile friendliness.

First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.

918 ms

Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.

1.30 s

Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.

4.82 s

Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.

0.001

Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.

9.87 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.

14.55 s

Page Load Progression

2.0 s
3.9 s
5.9 s
7.8 s
9.8 s
11.8 s
13.7 s
15.7 s
Checks
14
5 PASS 3 REVIEW 4 FIX
F
Page Weight Budget
Action
10.4 MB transferred, 522 requests
FIX
10.4 MB transferred, 522 requests
Critical::
Page weighs 22.2 MB (10.4 MB transferred)
Warning::
JavaScript is 5.1 MB — consider code splitting or lazy loading
Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.
Got: 5.1 MB
Warning::
Images are 5.0 MB — compress or use modern formats
Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.
Got: 5.0 MB
Warning::
522 HTTP requests — consider bundling or reducing
Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.
Info::
Estimated 2.2 g CO2 per page load
10.4 MB / 2.4 MB budget
10.4 MB transferred
522 requests
2.2 g CO2 per page load
JavaScript 5.1 MiB 49%
Images 5.0 MiB 48%
Fonts 116.6 KiB 1%
HTML 61.2 KiB 1%
Other 55.2 KiB 1%
Other 32.6 KiB 0%
Other 26.4 KiB 0%
CSS 23.3 KiB 0%
Other 5.9 KiB 0%
Other 0 B 0%
0 2.4 MB 4.9 MB
Over budget

Large JavaScript bundles delay interactivity. Split code by route or defer non-critical scripts.

Why this matters

JavaScript bundle is large — code-split routes and lazy-load off-screen components to defer.

Source: web.dev

Convert images to WebP/AVIF and resize to display dimensions to reduce transfer size.

Why this matters

Image bandwidth is high — modern formats (WebP/AVIF) and resizing typically cut it 50%+.

Source: web.dev

Each request adds latency. Bundle small files, use sprites, or eliminate unnecessary requests.

Why this matters

High HTTP request count — bundling, sprite-ing, and HTTP/2 server push can reduce per-request overhead.

Source: web.dev

D
Third-Party Impact
Action
99% third-party, 0 ms blocking
FIX
99% third-party, 0 ms blocking
Warning::
Third-party code accounts for 99% of page weight (10.3 MiB of 10.4 MiB)
Info::
Third-party blocking time is low (0 ms)
99%
First-party Third-party
F
JS Execution Cost
Action
16552ms total JS execution
FIX
16552ms total JS execution
Warning::
https://www.asahi.com/: 6631ms CPU time
Warning::
https://www.googletagmanager.com/gtm.js?id=GTM-K38...: 5771ms CPU time
Warning::
Unattributable: 1049ms CPU time
Warning::
https://securepubads.g.doubleclick.net/pagead/mana...: 343ms CPU time
Warning::
https://www.googletagmanager.com/gtm.js?id=GTM-K4N...: 292ms CPU time
Warning::
Third-party scripts: 9921ms (60% of total)

Main Thread Breakdown

Style & Layout 54% Script Evaluation 32% Other 9%
ScriptTotalScriptingParse/CompileParty
https://www.asahi.com/6631ms41ms2ms1st
https://www.googletagmanager.com/gtm.js?id=GTM-K38TZKV5771ms2036ms19ms3rd
Unattributable1049ms101ms0ms3rd
https://securepubads.g.doubleclick.net/pagead/managed/js/gpt/m202604060101/pubads_impl.js?cb=31097681343ms294ms15ms3rd
https://www.googletagmanager.com/gtm.js?id=GTM-K4N7QLF&gtm=4e6460292ms263ms20ms3rd
https://www.googletagmanager.com/gtag/js?id=AW-17575778725&cx=c&gtm=4e6460253ms218ms12ms3rd
https://www.googletagmanager.com/gtag/js?id=G-MCVDNZMSYQ&cx=c&gtm=4e6460196ms176ms18ms3rd
https://fundingchoicesmessages.google.com/f/AGSKWxWp7TmUoolMNio4htTu7IuM1KATunT3QAzwli6uu_IuxbRL6Q5CNB3i2i7AmSxXkLnsk9UvGes0AEMfHEK8M19OxpFNPpaDvmYl_wj3Ol8knuSR49PSlbUd1n6kYwVU7eSZqz4x9g==?fccs=W251bGwsbnVsbCxudWxsLG51bGwsbnVsbCxudWxsLFsxNzc1NTkyOTcwLDk4NTAwMDAwMF0sbnVsbCxudWxsLG51bGwsW251bGwsWzddXSwiaHR0cHM6Ly93d3cuYXNhaGkuY29tLyIsbnVsbCxbWzgsInlFQ3NHYndMaHhJIl0sWzksImVuLVVTIl0sWzE4LCJbW1tudWxsLDQ4MDhdXV0iXSxbMzUsIjE3NzU1OTI5NzAiXSxbMTksIjEiXSxbMTcsIlswXSJdLFsyNCwiIl0sWzI1LCJbWzk1Mzc5ODI0XV0iXSxbMjksImZhbHNlIl1dXQ177ms138ms11ms3rd
https://www.googletagmanager.com/gtm.js?id=GTM-N328R8158ms131ms18ms3rd
https://js.hs-analytics.net/analytics/1775592900000/6493544.js148ms97ms2ms3rd

Showing top 10 of 30 scripts

F
JS Bundles
Action
127 scripts, 1.9 MB unused
FIX
127 scripts, 1.9 MB unused
Warning::
https://securepubads.g.doubleclick.net/pagead/mana...: 124 KB unused (68%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://code.piano.io/api/tinypass.min.js: 82 KB unused (63%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/destination?...: 67 KB unused (47%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtag/destination?...: 67 KB unused (47%)
Consider code splitting or tree shaking to reduce unused code.
Warning::
https://www.googletagmanager.com/gtm.js?id=GTM-KX3...: 67 KB unused (48%)
Consider code splitting or tree shaking to reduce unused code.
Info::
Total unused JavaScript: 1.9 MB
1917 KB unused JavaScript

Downloaded but never executed on this page.

ScriptSizeUnusedMinifiedParty
https://securepubads.g.doubleclick.net/pagead/managed/js/gpt/m202604060101/pubads_impl.js?cb=31097681183 KB124 KB (68%)✓3rd
https://code.piano.io/api/tinypass.min.js132 KB82 KB (63%)✓3rd
https://www.googletagmanager.com/gtag/destination?id=AW-471014979&cx=c&gtm=4e6460144 KB67 KB (47%)✓3rd
https://www.googletagmanager.com/gtag/destination?id=AW-770377591&cx=c&gtm=4e6460144 KB67 KB (47%)✓3rd
https://www.googletagmanager.com/gtm.js?id=GTM-KX3Q99SS&l=itm_dl1_1014416139 KB67 KB (48%)✓3rd
https://www.googletagmanager.com/gtm.js?id=GTM-PJMVNDRF&l=itm_dl1_1024763139 KB67 KB (48%)✓3rd
https://www.googletagmanager.com/gtm.js?id=GTM-52RGTRCX&l=itm_dl1_1020617114 KB66 KB (58%)✓3rd
https://www.googletagmanager.com/gtag/destination?id=AW-10841393910&cx=c&gtm=4e6460137 KB66 KB (48%)✓3rd
https://www.googletagmanager.com/gtag/destination?id=AW-16679320228&cx=c&gtm=4e6460137 KB66 KB (48%)✓3rd
https://www.googletagmanager.com/gtag/destination?id=AW-865775659&cx=c&gtm=4e6460133 KB66 KB (49%)✓3rd

Consider code splitting or tree shaking to reduce unused code.

Why this matters

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.

Why this matters

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.

Why this matters

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.

Why this matters

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.

Why this matters

This bundle has high unused code — code-split or tree-shake to ship only what executes.

Source: web.dev / Lighthouse coverage

C
Image Optimization
Action
226 images, 0 KB saveable
REVIEW
226 images, 0 KB saveable
Warning::
https://www.asahicom.jp/rensai/images/genba_660x37... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.asahicom.jp/images/logo/top/logo_asm.s... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.asahicom.jp/images/logo/top/logo_andIl... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.asahicom.jp/images/logo/top/logo_andTr... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.asahicom.jp/images/logo/top/logo_globe... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.asahicom.jp/images/icon/top/icon__keyG... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.asahicom.jp/images/logo/top/logo_andM.... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.asahicom.jp/images/logo/top/logo_andMo... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.asahicom.jp/weather/images/hare_s.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.asahicom.jp/images23/fbox/edit5/202301... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.asahicom.jp/images/logo/top/logo_andHu... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.asahicom.jp/images/logo/top/logo_andW.... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.asahicom.jp/images/icon/top/icon__movi... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.asahicom.jp/images/logo_Think_Campus.p... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
https://www.asahicom.jp/special/images/hatarakutte... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
226 images 5.0 MB
0 oversized -0 KB
224 legacy format
15 missing dimensions CLS risk

Set explicit width and height to prevent CLS.

Why this matters

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.

Why this matters

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.

Why this matters

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.

Why this matters

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.

Why this matters

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.

Why this matters

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.

Why this matters

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.

Why this matters

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.

Why this matters

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.

Why this matters

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.

Why this matters

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.

Why this matters

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.

Why this matters

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.

Why this matters

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.

Why this matters

Image without explicit width/height — browser can't reserve space; CLS jumps when image loads.

Source: web.dev / Core Web Vitals

C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

B
HTTP Caching
max-age=0, no-cache
REVIEW
max-age=0, no-cache
Info::
Cache-Control header is set
Got: max-age=0, no-cache
Info::
ETag present — enables conditional (304) responses
Cache-Control

max-age=0, no-cache

DirectiveValueMeaning
max-age0Cache for 0 seconds
no-cache—Cache but always revalidate first
A+
Text Compression
All text resources are compressed
PASS
All text resources are compressed
Info::
All text resources are compressed
All text resources are properly compressed.
A+
Font Loading
5 fonts (117 KB)
PASS
5 fonts (117 KB)
Info::
5 font(s) use font-display: swap (FOUT risk but functional)

Web fonts

5

117 KB total

Render-blocking

0

of 5

Dominant font-display

swap

Most common across fonts

Font loading timeline
Transfer FOIT (block) FOUT (swap)
0 ms 500 ms 1.0 s FCP 918 ms LCP 1.3 shttps://fonts.gstatic.com/s/roboto/v48/KFOMCnqEu92Fr1ME7kSn66aGLdTylUAMQXC89YmC2DPNWubEbVmUiAr0klQmz24.woff2KFOMCnqEu92Fr1ME7kSn66a... https://fonts.gstatic.com/s/roboto/v48/KFOMCnqEu92Fr1ME7kSn66aGLdTylUAMQXC89YmC2DPNWubEbVmUiAr0klQmz24.woff2 — 14.8 KiB — 0 ms — font-display: swaphttps://fonts.gstatic.com/s/roboto/v48/KFOMCnqEu92Fr1ME7kSn66aGLdTylUAMQXC89YmC2DPNWubEbVn6iAr0klQmz24O0g.woff2KFOMCnqEu92Fr1ME7kSn66a... https://fonts.gstatic.com/s/roboto/v48/KFOMCnqEu92Fr1ME7kSn66aGLdTylUAMQXC89YmC2DPNWubEbVn6iAr0klQmz24O0g.woff2 — 6.7 KiB — 0 ms — font-display: swaphttps://fonts.gstatic.com/s/roboto/v51/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMa3yUBHMdazQ.woff2KFO7CnqEu92Fr1ME7kSn66a... https://fonts.gstatic.com/s/roboto/v51/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMa3yUBHMdazQ.woff2 — 36.7 KiB — 0 ms — font-display: swaphttps://fonts.gstatic.com/s/roboto/v51/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMaxKUBHMdazTgWw.woff2KFO7CnqEu92Fr1ME7kSn66a... https://fonts.gstatic.com/s/roboto/v51/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMaxKUBHMdazTgWw.woff2 — 16.3 KiB — 0 ms — font-display: swaphttps://fonts.gstatic.com/s/opensans/v40/memvYaGs126MiZpBA-UvWbX2vVnXBbObj2OVTS-mu0SC55I.woff2memvYaGs126MiZpBA-UvWbX... https://fonts.gstatic.com/s/opensans/v40/memvYaGs126MiZpBA-UvWbX2vVnXBbObj2OVTS-mu0SC55I.woff2 — 42.1 KiB — 0 ms — font-display: swap
KFOMCnqEu92Fr1ME7kSn66a... woff2 swap
Size 15 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
KFOMCnqEu92Fr1ME7kSn66a... woff2 swap
Size 7 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
KFO7CnqEu92Fr1ME7kSn66a... woff2 swap
Size 37 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
KFO7CnqEu92Fr1ME7kSn66a... woff2 swap
Size 16 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
memvYaGs126MiZpBA-UvWbX... woff2 swap
Size 42 KB
Load time 0 ms
Start 0 ms
Risk FOUT — text flashes from fallback to web font
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 Caching
All resources properly cached
PASS
All resources properly cached
Info::
No caching issues found
All static resources have appropriate caching headers.
A+
Critical Rendering Path
No render-blocking resources
PASS
No render-blocking resources
Info::
No render-blocking resources detected
A+
Resource Hints
No optimization needed
PASS
No optimization needed
Info::
No resource hint issues
Network Waterfall
522 requests over 0ms
INFO

Performance analysis not available for this result.

Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
60% of JavaScript execution is third-party
First-party Third-party 9921ms · 3311KB · ¥59/mo
Google Tag Manager
Tag Manager
Costly
Execution 5771ms
Transfer 197 KB
Unused 30%
Monthly Cost ¥34/mo
Unattributable
Other
Costly
Execution 1049ms
Transfer 0 KB
Monthly Cost ¥6/mo
securepubads.g.doubleclick.net
Other
Costly
Execution 343ms
Transfer 183 KB
Unused 68%
Monthly Cost ¥2/mo
Google Tag Manager
Tag Manager
Costly
Execution 292ms
Transfer 176 KB
Unused 31%
Monthly Cost ¥2/mo
Google Tag Manager
Tag Manager
Costly
Execution 253ms
Transfer 143 KB
Unused 43%
Monthly Cost ¥2/mo
Google Tag Manager
Tag Manager
Optional
Execution 196ms
Transfer 173 KB
Unused 34%
Monthly Cost ¥1/mo
fundingchoicesmessages.google.com
Other
Optional
Execution 177ms
Transfer 68 KB
Monthly Cost ¥1/mo
Google Tag Manager
Tag Manager
Optional
Execution 158ms
Transfer 167 KB
Unused 39%
Monthly Cost ¥1/mo
HubSpot Analytics
Analytics
Optional
Execution 148ms
Transfer 42 KB
Monthly Cost ¥1/mo
cdn.cxense.com
Other
Optional
Execution 132ms
Transfer 38 KB
Monthly Cost ¥1/mo
micro.rubiconproject.com
Other
Optional
Execution 117ms
Transfer 188 KB
Unused 33%
Monthly Cost ¥1/mo
Google Tag Manager
Tag Manager
Optional
Execution 109ms
Transfer 143 KB
Unused 43%
Monthly Cost ¥1/mo
code.piano.io
Other
Optional
Execution 102ms
Transfer 132 KB
Unused 63%
Monthly Cost ¥1/mo
fundingchoicesmessages.google.com
Other
Optional
Execution 89ms
Transfer 70 KB
Unused 52%
Monthly Cost ¥1/mo
c.amazon-adsystem.com
Other
Optional
Execution 89ms
Transfer 90 KB
Unused 43%
Monthly Cost ¥1/mo
Google Tag Manager
Tag Manager
Optional
Execution 74ms
Transfer 144 KB
Unused 47%
Monthly Cost ¥0/mo
Google Tag Manager
Tag Manager
Optional
Execution 72ms
Transfer 144 KB
Unused 47%
Monthly Cost ¥0/mo
Google Tag Manager
Tag Manager
Optional
Execution 70ms
Transfer 137 KB
Unused 48%
Monthly Cost ¥0/mo
Google Tag Manager
Tag Manager
Optional
Execution 70ms
Transfer 133 KB
Unused 49%
Monthly Cost ¥0/mo
analytics.tiktok.com
Other
Optional
Execution 68ms
Transfer 106 KB
Unused 54%
Monthly Cost ¥0/mo
Google Tag Manager
Tag Manager
Optional
Execution 68ms
Transfer 137 KB
Unused 48%
Monthly Cost ¥0/mo
Facebook Pixel
Advertising
Optional
Execution 65ms
Transfer 22 KB
Monthly Cost ¥0/mo
dynamic.criteo.com
Other
Optional
Execution 61ms
Transfer 25 KB
Monthly Cost ¥0/mo
Facebook Pixel
Advertising
Optional
Execution 61ms
Transfer 97 KB
Unused 27%
Monthly Cost ¥0/mo
Twitter/X Pixel
Advertising
Optional
Execution 60ms
Transfer 13 KB
Monthly Cost ¥0/mo
Google Tag Manager
Tag Manager
Optional
Execution 59ms
Transfer 133 KB
Unused 49%
Monthly Cost ¥0/mo
Google Tag Manager
Tag Manager
Optional
Execution 58ms
Transfer 137 KB
Unused 48%
Monthly Cost ¥0/mo
Google Tag Manager
Tag Manager
Optional
Execution 56ms
Transfer 137 KB
Unused 48%
Monthly Cost ¥0/mo
Google Tag Manager
Tag Manager
Optional
Execution 53ms
Transfer 139 KB
Unused 48%
Monthly Cost ¥0/mo

These scripts may cost more than they're worth

  • Google Tag Manager adds 5771ms and costs ~¥34/month
  • Unattributable adds 1049ms and costs ~¥6/month
  • securepubads.g.doubleclick.net adds 343ms and costs ~¥2/month
  • Google Tag Manager adds 292ms and costs ~¥2/month
  • Google Tag Manager adds 253ms and costs ~¥2/month

60% of JavaScript execution time comes from third-party scripts.

Why this matters

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

Google Tag Manager takes 5771ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

Unattributable takes 1049ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

securepubads.g.doubleclick.net takes 343ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

68% of securepubads.g.doubleclick.net's code is unused. The script may be loading features you don't use.

Why this matters

Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.

Source: web.dev

Google Tag Manager takes 292ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

Google Tag Manager takes 253ms of CPU time. Consider loading it asynchronously or replacing it with a lighter alternative.

Why this matters

This script has high main-thread execution time — optimize hot paths or defer.

Source: web.dev

63% of code.piano.io's code is unused. The script may be loading features you don't use.

Why this matters

Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.

Source: web.dev

52% of fundingchoicesmessages.google.com's code is unused. The script may be loading features you don't use.

Why this matters

Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.

Source: web.dev

54% of analytics.tiktok.com's code is unused. The script may be loading features you don't use.

Why this matters

Bundle has high unused-code ratio — tree-shaking and route-splitting recover the wasted bytes.

Source: web.dev

How third-party costs are calculated

All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

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