Skip to content
https://jugem.jp

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
70
GRADE
C
FIX
2
REVIEW
3
PASS
1
INFO
0
Device:
Mobile Desktop
Checks
6
1 PASS 3 REVIEW 2 FIX
D
Green Hosting
Action
Unknown
FIX
Unknown
Info::
Hosting provider could not be identified
Without knowing the provider, we cannot determine their energy sourcing. Check with your hosting provider about their renewable energy commitments.
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 HostingUnable to Determine
Hosting Not identified✗CDN Not identified✗

Based on known provider commitments. Verify at thegreenwebfoundation.org

D
Carbon Budget
Action
54th percentile
FIX
54th percentile
Warning::
0.76g CO2 — above the median website (0.60g)
Heavier than an estimated 46% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 54th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.76g

54th percentile

Cleaner than 46% of websites

✗ Above the median website

vs Median 27% more
vs Target 52% more
B
CO2 Per Page Load
0.76g CO2 per view
REVIEW
0.76g CO2 per view
Info::
0.76g CO2 per page view
This page transfers 2.7 MB, producing an estimated 0.76g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.14g, network 0.13g, end-user device 0.49g.
Got: 0.76g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 91.1 kg CO2/year
With 10,000 page views per month, this page would generate approximately 91.1 kg of CO2 annually — equivalent to charging 11391 smartphones.

0.76g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 46% of websites

Sustainable Web Design model v4 · Page size: 2.7 MB

Your site
0.76g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.14g
Network
0.13g
End-user device
0.49g
At 10,000 monthly views: Monthly: 7.6 kg · Annual: 91.1 kg · ≈ 11391 smartphone charges
B
Transfer Efficiency
80% efficient
REVIEW
80% efficient
Info::
Transfer efficiency: 80%
An estimated 562 KB (20%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 562 KB of unused JavaScript. This wasted data produces 0.16g of unnecessary CO2 per page view.
80% efficient

Total waste: 562 KB (20% of page weight)

Unused JS 562 KB

0.16g unnecessary CO2 per visit

Actual transfer 2746 KB
Theoretical minimum 2183 KB
Potential savings 562 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
99% cached
PASS
99% cached
Info::
99% reduction on repeat visits
Returning visitors download only 21 KB (vs 2746 KB first visit). 180 of 185 resources are served from browser cache, saving 0.75g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.76g)
First visit
2746 KB
Repeat visit
21 KB

99% reduction on repeat visits

Saving 0.75g CO2 per returning visitor

180 resources served from cache · 5 resources re-downloaded

All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

Send Feedback