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https://rki.de

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
52
GRADE
F
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
1.94g CO2 per view
FIX
1.94g CO2 per view
Warning::
1.94g CO2 per page view
This page transfers 6.9 MB, producing an estimated 1.94g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.36g, network 0.34g, end-user device 1.25g.
Got: 1.94g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 233.3 kg CO2/year
With 10,000 page views per month, this page would generate approximately 233.3 kg of CO2 annually — equivalent to charging 29163 smartphones.

1.94g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 12% of websites

Sustainable Web Design model v4 · Page size: 6.9 MB

Your site
1.94g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.36g
Network
0.34g
End-user device
1.25g
At 10,000 monthly views: Monthly: 19.4 kg · Annual: 233.3 kg · ≈ 29163 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 Apache HTTP Server✗CDN Not identified✗

Based on known provider commitments. Verify at thegreenwebfoundation.org

F
Carbon Budget
Action
88th percentile
FIX
88th percentile
Warning::
1.94g CO2 — above the median website (0.60g)
Heavier than an estimated 12% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 88th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

1.94g

88th percentile

Cleaner than 12% of websites

✗ Above the median website

vs Median 224% more
vs Target 289% more
C
Transfer Efficiency
Action
74% efficient
REVIEW
74% efficient
Warning::
Transfer efficiency: 74%
An estimated 1826 KB (26%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 1826 KB of unused JavaScript. This wasted data produces 0.51g of unnecessary CO2 per page view.
74% efficient

Total waste: 1826 KB (26% of page weight)

Unused JS 1826 KB

0.51g unnecessary CO2 per visit

Actual transfer 7030 KB
Theoretical minimum 5203 KB
Potential savings 1826 KB (0.51g 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 206 KB (vs 7030 KB first visit). 33 of 34 resources are served from browser cache, saving 1.89g CO2 per repeat visit.
Info::
Repeat visit: 0.06g CO2 (first visit: 1.94g)
First visit
7030 KB
Repeat visit
206 KB

97% reduction on repeat visits

Saving 1.89g CO2 per returning visitor

33 resources served from cache · 1 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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