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https://uni-hannover.de

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
68
GRADE
D
FIX
2
REVIEW
3
PASS
1
INFO
0
Device:
Mobile Desktop
Checks
6
1 PASS 3 REVIEW 2 FIX
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

D
Carbon Budget
Action
54th percentile
FIX
54th percentile
Warning::
0.77g 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

0.77g

54th percentile

Cleaner than 46% of websites

✗ Above the median website

vs Median 28% more
vs Target 53% more
B
CO2 Per Page Load
0.77g CO2 per view
REVIEW
0.77g CO2 per view
Info::
0.77g CO2 per page view
This page transfers 2.7 MB, producing an estimated 0.77g 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: 0.77g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 91.8 kg CO2/year
With 10,000 page views per month, this page would generate approximately 91.8 kg of CO2 annually — equivalent to charging 11477 smartphones.

0.77g

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
0.77g
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: 7.7 kg · Annual: 91.8 kg · ≈ 11477 smartphone charges
B
Transfer Efficiency
87% efficient
REVIEW
87% efficient
Info::
Transfer efficiency: 87%
An estimated 370 KB (13%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 370 KB of unused JavaScript. This wasted data produces 0.10g of unnecessary CO2 per page view.
87% efficient

Total waste: 370 KB (13% of page weight)

Unused JS 370 KB

0.10g unnecessary CO2 per visit

Actual transfer 2766 KB
Theoretical minimum 2396 KB
Potential savings 370 KB (0.10g 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 2766 KB first visit). 123 of 125 resources are served from browser cache, saving 0.76g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.77g)
First visit
2766 KB
Repeat visit
19 KB

99% reduction on repeat visits

Saving 0.76g CO2 per returning visitor

123 resources served from cache · 2 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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