Browsers will use heuristic caching, which can be unpredictable. Set explicit cache headers.
No Cache-Control header
Adding a Cache-Control header can significantly improve repeat-visit performance.
C
Image Optimization
Action
39 images, 0 KB saveable
REVIEW
39 images, 0 KB saveable
Warning::
!
https://www.ameba.jp/images/organizers/AmebaChoice... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.ameba.jp/images/organizers/AmebaChoice... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.ameba.jp/images/organizers/AmebaChoice... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.ameba.jp/images/organizers/AmebaChoice... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.ameba.jp/images/organizers/AmebaChoice... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.ameba.jp/images/common/logo.png is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.ameba.jp/images/organizers/AmebaChoice... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.ameba.jp/images/organizers/AmebaChoice... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.ameba.jp/images/organizers/AmebaChoice... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.ameba.jp/images/organizers/AmebaChoice... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.ameba.jp/images/organizers/AmebaChoice... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.ameba.jp/images/organizers/AmebaChoice... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.ameba.jp/images/organizers/AmebaChoice... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.ameba.jp/images/organizers/AmebaChoice... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.ameba.jp/images/organizers/AmebaChoice... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.ameba.jp/images/organizers/AmebaChoice... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.ameba.jp/images/organizers/AmebaChoice... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
Warning::
!
https://www.ameba.jp/images/organizers/AmebaChoice... is missing width/height — may cause layout shift
Set explicit width and height to prevent CLS.
39images1.4 MB
0oversized-0 KB
37legacy format
18missing dimensionsCLS 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
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
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
2 fonts (96 KB)
PASS
2 fonts (96 KB)
Info::
i
2 font(s) use font-display: swap (FOUT risk but functional)
Web fonts
2
96 KB total
Render-blocking
0
of 2
Dominant font-display
swap
Most common across fonts
Font loading timeline
TransferFOIT (block)FOUT (swap)
amebasymbolsv3.woffwoffswap
Size54 KB
Load time4 ms
Start4.9 s
RiskFOUT — text flashes from fallback to web font
Convert to woff2 for ~30% smaller file size
memvYaGs126MiZpBA-UvWbX...woff2swap
Size42 KB
Load time68 ms
Start5.9 s
RiskFOUT — 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)
Fixing the unchecked items could save ~16 KB and ~32 ms
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
A+
Render-Blocking Resources
No render-blocking resources detected
PASS
No render-blocking resources detected
Info::
✓
No render-blocking resources detected in <head>
A+
Third-Party Resources
No third-party resources detected
PASS
No third-party resources detected
Network Waterfall
97 requests over 9932ms
INFO
HTML JavaScript CSS Images Fonts XHR/Fetch Other
Third-Party Script Cost
Per-script blocking time, transfer cost, and cache headers
INFO
100%of JavaScript execution is third-party
First-party Third-party4282ms · 1209KB · ¥5918/mo
Script
Category
Execution
Transfer
Unused
Monthly Cost
Verdict
www.ameba.jp
www.ameba.jp
Other
935ms
35 KB
—
¥1292/mo
Costly
Unattributable
Unattributable
Other
642ms
0 KB
—
¥888/mo
Costly
fundingchoicesmessages.google.com
fundingchoicesmessages.google.com
Other
505ms
68 KB
—
¥697/mo
Costly
www.ameba.jp
www.ameba.jp
Other
480ms
128 KB
40%
¥663/mo
Costly
securepubads.g.doubleclick.net
securepubads.g.doubleclick.net
Other
249ms
188 KB
71%
¥344/mo
Costly
Microsoft Clarity
scripts.clarity.ms
Session Replay
222ms
26 KB
—
¥306/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
208ms
157 KB
41%
¥288/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
208ms
157 KB
42%
¥288/mo
Costly
fundingchoicesmessages.google.com
fundingchoicesmessages.google.com
Other
204ms
70 KB
53%
¥282/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
200ms
164 KB
45%
¥276/mo
Costly
www.ameba.jp
www.ameba.jp
Other
188ms
37 KB
55%
¥260/mo
Costly
Google Tag Manager
www.googletagmanager.com
Tag Manager
170ms
145 KB
42%
¥235/mo
Costly
www.googletagservices.com
www.googletagservices.com
Other
71ms
34 KB
—
¥98/mo
Costly
www.ameba.jp
Other
Costly
Execution935ms
Transfer35 KB
Monthly Cost¥1292/mo
Unattributable
Other
Costly
Execution642ms
Transfer0 KB
Monthly Cost¥888/mo
fundingchoicesmessages.google.com
Other
Costly
Execution505ms
Transfer68 KB
Monthly Cost¥697/mo
www.ameba.jp
Other
Costly
Execution480ms
Transfer128 KB
Unused40%
Monthly Cost¥663/mo
securepubads.g.doubleclick.net
Other
Costly
Execution249ms
Transfer188 KB
Unused71%
Monthly Cost¥344/mo
Microsoft Clarity
Session Replay
Costly
Execution222ms
Transfer26 KB
Monthly Cost¥306/mo
Google Tag Manager
Tag Manager
Costly
Execution208ms
Transfer157 KB
Unused41%
Monthly Cost¥288/mo
Google Tag Manager
Tag Manager
Costly
Execution208ms
Transfer157 KB
Unused42%
Monthly Cost¥288/mo
fundingchoicesmessages.google.com
Other
Costly
Execution204ms
Transfer70 KB
Unused53%
Monthly Cost¥282/mo
Google Tag Manager
Tag Manager
Costly
Execution200ms
Transfer164 KB
Unused45%
Monthly Cost¥276/mo
www.ameba.jp
Other
Costly
Execution188ms
Transfer37 KB
Unused55%
Monthly Cost¥260/mo
Google Tag Manager
Tag Manager
Costly
Execution170ms
Transfer145 KB
Unused42%
Monthly Cost¥235/mo
www.googletagservices.com
Other
Costly
Execution71ms
Transfer34 KB
Monthly Cost¥98/mo
These scripts may cost more than they're worth
www.ameba.jp adds 935ms and costs ~¥1292/month
Unattributable adds 642ms and costs ~¥888/month
fundingchoicesmessages.google.com adds 505ms and costs ~¥697/month
www.ameba.jp adds 480ms and costs ~¥663/month
securepubads.g.doubleclick.net adds 249ms and costs ~¥344/month
Microsoft Clarity adds 222ms and costs ~¥306/month
Google Tag Manager adds 208ms and costs ~¥288/month
Google Tag Manager adds 208ms and costs ~¥288/month
fundingchoicesmessages.google.com adds 204ms and costs ~¥282/month
Google Tag Manager adds 200ms and costs ~¥276/month
www.ameba.jp adds 188ms and costs ~¥260/month
Google Tag Manager adds 170ms and costs ~¥235/month
www.googletagservices.com adds 71ms and costs ~¥98/month
100% of JavaScript execution time is spent on third-party scripts. Consider auditing which scripts are essential.
Why this matters
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.ameba.jp takes 935ms 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 642ms 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
fundingchoicesmessages.google.com takes 505ms 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
www.ameba.jp takes 480ms 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 249ms 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
71% 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
Microsoft Clarity takes 222ms 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 208ms 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 208ms 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
fundingchoicesmessages.google.com takes 204ms 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
53% 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
Google Tag Manager takes 200ms 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
www.ameba.jp takes 188ms 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
55% of www.ameba.jp'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 170ms 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
www.googletagservices.com takes 71ms 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.