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https://uni-bonn.de

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
73
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
0.51g CO2 per view
REVIEW
0.51g CO2 per view
Info::
0.51g CO2 per page view
This page transfers 1.8 MB, producing an estimated 0.51g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.09g, network 0.09g, end-user device 0.33g.
Got: 0.51g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 60.9 kg CO2/year
With 10,000 page views per month, this page would generate approximately 60.9 kg of CO2 annually — equivalent to charging 7615 smartphones.

0.51g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 60% of websites

Sustainable Web Design model v4 · Page size: 1.8 MB

Your site
0.51g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.09g
Network
0.09g
End-user device
0.33g
At 10,000 monthly views: Monthly: 5.1 kg · Annual: 60.9 kg · ≈ 7615 smartphone charges
B
Carbon Budget
40th percentile
REVIEW
40th percentile
Info::
0.51g CO2 — below the median website (0.60g)
Better than an estimated 60% of websites, but above the sustainability target of 0.50g. Reducing page weight would help reach the target.
Info::
Estimated 40th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.51g

40th percentile

Cleaner than 60% of websites

✗ Above the median website

vs Median 15% cleaner ✓
vs Target 2% more
C
Transfer Efficiency
Action
73% efficient
REVIEW
73% efficient
Warning::
Transfer efficiency: 73%
An estimated 501 KB (27%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 501 KB of unused JavaScript. This wasted data produces 0.14g of unnecessary CO2 per page view.
73% efficient

Total waste: 501 KB (27% of page weight)

Unused JS 501 KB

0.14g unnecessary CO2 per visit

Actual transfer 1835 KB
Theoretical minimum 1334 KB
Potential savings 501 KB (0.14g 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 1835 KB first visit). 43 of 44 resources are served from browser cache, saving 0.50g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.51g)
First visit
1835 KB
Repeat visit
19 KB

99% reduction on repeat visits

Saving 0.50g CO2 per returning visitor

43 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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