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https://zdf.de

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
57
GRADE
D
FIX
3
REVIEW
1
PASS
2
INFO
0
Device:
Mobile Desktop
Checks
6
2 PASS 1 REVIEW 3 FIX
F
CO2 Per Page Load
Action
2.34g CO2 per view
FIX
2.34g CO2 per view
Critical::
2.34g CO2 per page view
This page transfers 8.3 MB, producing an estimated 2.34g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.43g, network 0.40g, end-user device 1.50g.
Got: 2.34g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 281.1 kg CO2/year
With 10,000 page views per month, this page would generate approximately 281.1 kg of CO2 annually — equivalent to charging 35138 smartphones.

2.34g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 5% of websites

Sustainable Web Design model v4 · Page size: 8.3 MB

Your site
2.34g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.43g
Network
0.40g
End-user device
1.50g
At 10,000 monthly views: Monthly: 23.4 kg · Annual: 281.1 kg · ≈ 35138 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 Next.js✗CDN Not identified✗

Based on known provider commitments. Verify at thegreenwebfoundation.org

F
Carbon Budget
Action
95th percentile
FIX
95th percentile
Warning::
2.34g CO2 — above the median website (0.60g)
Heavier than an estimated 5% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 95th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

2.34g

95th percentile

Cleaner than 5% of websites

✗ Above the median website

vs Median 290% more
vs Target 369% more
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A+
Repeat Visit Weight
95% cached
PASS
95% cached
Info::
95% reduction on repeat visits
Returning visitors download only 428 KB (vs 8470 KB first visit). 378 of 379 resources are served from browser cache, saving 2.22g CO2 per repeat visit.
Info::
Repeat visit: 0.12g CO2 (first visit: 2.34g)
First visit
8470 KB
Repeat visit
428 KB

95% reduction on repeat visits

Saving 2.22g CO2 per returning visitor

378 resources served from cache · 1 resources re-downloaded

A+
Transfer Efficiency
97% efficient
PASS
97% efficient
Info::
Transfer efficiency: 97%
Only 212 KB of potential savings identified. Your page is well-optimized for size.
97% efficient

Total waste: 212 KB (3% of page weight)

Unused JS 212 KB

0.06g unnecessary CO2 per visit

Actual transfer 8470 KB
Theoretical minimum 8257 KB
Potential savings 212 KB (0.06g CO2)

See Deep Analysis sections above for specific optimizations.

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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