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https://kfw.de

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
1
REVIEW
4
PASS
1
INFO
0
Device:
Mobile Desktop
Checks
6
1 PASS 4 REVIEW 1 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

B
CO2 Per Page Load
0.55g CO2 per view
REVIEW
0.55g CO2 per view
Info::
0.55g CO2 per page view
This page transfers 2.0 MB, producing an estimated 0.55g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.10g, network 0.10g, end-user device 0.36g.
Got: 0.55g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 66.6 kg CO2/year
With 10,000 page views per month, this page would generate approximately 66.6 kg of CO2 annually — equivalent to charging 8320 smartphones.

0.55g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 55% of websites

Sustainable Web Design model v4 · Page size: 2.0 MB

Your site
0.55g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.10g
Network
0.10g
End-user device
0.36g
At 10,000 monthly views: Monthly: 5.5 kg · Annual: 66.6 kg · ≈ 8320 smartphone charges
B
Carbon Budget
45th percentile
REVIEW
45th percentile
Info::
0.55g CO2 — below the median website (0.60g)
Better than an estimated 55% of websites, but above the sustainability target of 0.50g. Reducing page weight would help reach the target.
Info::
Estimated 45th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.55g

45th percentile

Cleaner than 55% of websites

✗ Above the median website

vs Median 8% cleaner ✓
vs Target 11% more
C
Transfer Efficiency
Action
74% efficient
REVIEW
74% efficient
Warning::
Transfer efficiency: 74%
An estimated 524 KB (26%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 524 KB of unused JavaScript. This wasted data produces 0.15g of unnecessary CO2 per page view.
74% efficient

Total waste: 524 KB (26% of page weight)

Unused JS 524 KB

0.15g unnecessary CO2 per visit

Actual transfer 2005 KB
Theoretical minimum 1480 KB
Potential savings 524 KB (0.15g 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 19 KB (vs 2005 KB first visit). 84 of 87 resources are served from browser cache, saving 0.55g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.55g)
First visit
2005 KB
Repeat visit
19 KB

99% reduction on repeat visits

Saving 0.55g CO2 per returning visitor

84 resources served from cache · 3 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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