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https://mynavi.jp

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
54
GRADE
F
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
4.75g CO2 per view
FIX
4.75g CO2 per view
Critical::
4.75g CO2 per page view
This page transfers 16.8 MB, producing an estimated 4.75g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.88g, network 0.82g, end-user device 3.05g.
Got: 4.75g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 569.5 kg CO2/year
With 10,000 page views per month, this page would generate approximately 569.5 kg of CO2 annually — equivalent to charging 71184 smartphones.

4.75g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 5% of websites

Sustainable Web Design model v4 · Page size: 16.8 MB

Your site
4.75g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.88g
Network
0.82g
End-user device
3.05g
At 10,000 monthly views: Monthly: 47.5 kg · Annual: 569.5 kg · ≈ 71184 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
95th percentile
FIX
95th percentile
Warning::
4.75g 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

4.75g

95th percentile

Cleaner than 5% of websites

✗ Above the median website

vs Median 691% more
vs Target 849% 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 8 KB (vs 17159 KB first visit). 60 of 61 resources are served from browser cache, saving 4.74g CO2 per repeat visit.
Info::
Repeat visit: 0.00g CO2 (first visit: 4.75g)
First visit
17159 KB
Repeat visit
8 KB

100% reduction on repeat visits

Saving 4.74g CO2 per returning visitor

60 resources served from cache · 1 resources re-downloaded

A+
Transfer Efficiency
99% efficient
PASS
99% efficient
Info::
Transfer efficiency: 99%
Only 189 KB of potential savings identified. Your page is well-optimized for size.
99% efficient

Total waste: 189 KB (1% of page weight)

Unused JS 189 KB

0.05g unnecessary CO2 per visit

Actual transfer 17159 KB
Theoretical minimum 16969 KB
Potential savings 189 KB (0.05g 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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