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https://so-net.ne.jp

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
57
GRADE
D
FIX
3
REVIEW
1
PASS
2
INFO
0
Device:
Mobile Desktop
Checks
6
2 PASS 1 REVIEW 3 FIX
F
CO2 Per Page Load
Action
2.70g CO2 per view
FIX
2.70g CO2 per view
Critical::
2.70g CO2 per page view
This page transfers 9.5 MB, producing an estimated 2.70g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.50g, network 0.47g, end-user device 1.73g.
Got: 2.70g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 323.9 kg CO2/year
With 10,000 page views per month, this page would generate approximately 323.9 kg of CO2 annually — equivalent to charging 40482 smartphones.

2.70g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 5% of websites

Sustainable Web Design model v4 · Page size: 9.5 MB

Your site
2.70g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.50g
Network
0.47g
End-user device
1.73g
At 10,000 monthly views: Monthly: 27.0 kg · Annual: 323.9 kg · ≈ 40482 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::
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 Amazon Web Services✗CDN Not identified✗

Based on known provider commitments. Verify at thegreenwebfoundation.org

F
Carbon Budget
Action
95th percentile
FIX
95th percentile
Warning::
2.70g CO2 — above the median website (0.60g)
Heavier than an estimated 5% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 95th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

2.70g

95th percentile

Cleaner than 5% of websites

✗ Above the median website

vs Median 350% more
vs Target 440% more
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A+
Repeat Visit Weight
100% cached
PASS
100% cached
Info::
100% reduction on repeat visits
Returning visitors download only 25 KB (vs 9758 KB first visit). 281 of 285 resources are served from browser cache, saving 2.69g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 2.70g)
First visit
9758 KB
Repeat visit
25 KB

100% reduction on repeat visits

Saving 2.69g CO2 per returning visitor

281 resources served from cache · 4 resources re-downloaded

A+
Transfer Efficiency
91% efficient
PASS
91% efficient
Info::
Transfer efficiency: 91%
Only 868 KB of potential savings identified. Your page is well-optimized for size.
91% efficient

Total waste: 868 KB (9% of page weight)

Unused JS 868 KB

0.24g unnecessary CO2 per visit

Actual transfer 9758 KB
Theoretical minimum 8890 KB
Potential savings 868 KB (0.24g CO2)

See Deep Analysis sections above for specific optimizations.

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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