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https://b.hatena.ne.jp

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
64
GRADE
D
FIX
3
REVIEW
2
PASS
1
INFO
0
Device:
Mobile Desktop
Checks
6
1 PASS 2 REVIEW 3 FIX
F
CO2 Per Page Load
Action
1.55g CO2 per view
FIX
1.55g CO2 per view
Warning::
1.55g CO2 per page view
This page transfers 5.5 MB, producing an estimated 1.55g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.29g, network 0.27g, end-user device 1.00g.
Got: 1.55g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 186.5 kg CO2/year
With 10,000 page views per month, this page would generate approximately 186.5 kg of CO2 annually — equivalent to charging 23315 smartphones.

1.55g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 23% of websites

Sustainable Web Design model v4 · Page size: 5.5 MB

Your site
1.55g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.29g
Network
0.27g
End-user device
1.00g
At 10,000 monthly views: Monthly: 15.5 kg · Annual: 186.5 kg · ≈ 23315 smartphone charges
D
Green Hosting
Action
Not green
FIX
Not green
Info::
No confirmed renewable energy commitment detected
Consider providers like Cloudflare, Google Cloud, or Vercel that match 100% of their energy use with renewables.
Info::
AWS: Renewable energy varies by region; committed to 100% by 2025
Info::
AWS CloudFront: Renewable varies by edge location
Info::
Green hosting status based on known provider commitments
Green hosting detection uses a curated database of provider renewable energy commitments. This is not a real-time verification. For authoritative checks, visit thegreenwebfoundation.org.
Green HostingNot Green Hosted
Hosting AWS✗CDN AWS CloudFront✗

AWS: Renewable energy varies by region; committed to 100% by 2025

AWS CloudFront: Renewable varies by edge location

Based on known provider commitments. Verify at thegreenwebfoundation.org

F
Carbon Budget
Action
77th percentile
FIX
77th percentile
Warning::
1.55g CO2 — above the median website (0.60g)
Heavier than an estimated 23% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 77th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

1.55g

77th percentile

Cleaner than 23% of websites

✗ Above the median website

vs Median 159% more
vs Target 211% more
B
Transfer Efficiency
90% efficient
REVIEW
90% efficient
Info::
Transfer efficiency: 90%
An estimated 565 KB (10%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 565 KB of unused JavaScript. This wasted data produces 0.16g of unnecessary CO2 per page view.
90% efficient

Total waste: 565 KB (10% of page weight)

Unused JS 565 KB

0.16g unnecessary CO2 per visit

Actual transfer 5620 KB
Theoretical minimum 5054 KB
Potential savings 565 KB (0.16g CO2)

See Deep Analysis sections above for specific optimizations.

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

Green Hosting

No green hosting detected

A+
Repeat Visit Weight
98% cached
PASS
98% cached
Info::
98% reduction on repeat visits
Returning visitors download only 125 KB (vs 5620 KB first visit). 405 of 418 resources are served from browser cache, saving 1.52g CO2 per repeat visit.
Info::
Repeat visit: 0.03g CO2 (first visit: 1.55g)
First visit
5620 KB
Repeat visit
125 KB

98% reduction on repeat visits

Saving 1.52g CO2 per returning visitor

405 resources served from cache · 13 resources re-downloaded

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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