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https://rakuten.com

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
D
CO2 Per Page Load
Action
1.31g CO2 per view
FIX
1.31g CO2 per view
Warning::
1.31g CO2 per page view
This page transfers 4.6 MB, producing an estimated 1.31g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.24g, network 0.23g, end-user device 0.84g.
Got: 1.31g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 156.9 kg CO2/year
With 10,000 page views per month, this page would generate approximately 156.9 kg of CO2 annually — equivalent to charging 19613 smartphones.

1.31g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 30% of websites

Sustainable Web Design model v4 · Page size: 4.6 MB

Your site
1.31g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.24g
Network
0.23g
End-user device
0.84g
At 10,000 monthly views: Monthly: 13.1 kg · Annual: 156.9 kg · ≈ 19613 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 Next.js✗CDN Not identified✗

Based on known provider commitments. Verify at thegreenwebfoundation.org

D
Carbon Budget
Action
70th percentile
FIX
70th percentile
Warning::
1.31g CO2 — above the median website (0.60g)
Heavier than an estimated 30% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 70th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

1.31g

70th percentile

Cleaner than 30% of websites

✗ Above the median website

vs Median 118% more
vs Target 162% more
B
Transfer Efficiency
75% efficient
REVIEW
75% efficient
Info::
Transfer efficiency: 75%
An estimated 1176 KB (25%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 1176 KB of unused JavaScript. This wasted data produces 0.33g of unnecessary CO2 per page view.
75% efficient

Total waste: 1176 KB (25% of page weight)

Unused JS 1176 KB

0.33g unnecessary CO2 per visit

Actual transfer 4727 KB
Theoretical minimum 3551 KB
Potential savings 1176 KB (0.33g 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
97% cached
PASS
97% cached
Info::
97% reduction on repeat visits
Returning visitors download only 123 KB (vs 4727 KB first visit). 276 of 282 resources are served from browser cache, saving 1.27g CO2 per repeat visit.
Info::
Repeat visit: 0.03g CO2 (first visit: 1.31g)
First visit
4727 KB
Repeat visit
123 KB

97% reduction on repeat visits

Saving 1.27g CO2 per returning visitor

276 resources served from cache · 6 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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