Skip to content
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
2.44g CO2 per view
FIX
2.44g CO2 per view
Critical::
2.44g CO2 per page view
This page transfers 8.6 MB, producing an estimated 2.44g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.45g, network 0.42g, end-user device 1.56g.
Got: 2.44g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 292.4 kg CO2/year
With 10,000 page views per month, this page would generate approximately 292.4 kg of CO2 annually — equivalent to charging 36544 smartphones.

2.44g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 5% of websites

Sustainable Web Design model v4 · Page size: 8.6 MB

Your site
2.44g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.45g
Network
0.42g
End-user device
1.56g
At 10,000 monthly views: Monthly: 24.4 kg · Annual: 292.4 kg · ≈ 36544 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::
2.44g 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

2.44g

95th percentile

Cleaner than 5% of websites

✗ Above the median website

vs Median 306% more
vs Target 387% 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 8809 KB first visit). 298 of 299 resources are served from browser cache, saving 2.32g CO2 per repeat visit.
Info::
Repeat visit: 0.12g CO2 (first visit: 2.44g)
First visit
8809 KB
Repeat visit
428 KB

95% reduction on repeat visits

Saving 2.32g CO2 per returning visitor

298 resources served from cache · 1 resources re-downloaded

A+
Transfer Efficiency
97% efficient
PASS
97% efficient
Info::
Transfer efficiency: 97%
Only 235 KB of potential savings identified. Your page is well-optimized for size.
97% efficient

Total waste: 235 KB (3% of page weight)

Unused JS 235 KB

0.07g unnecessary CO2 per visit

Actual transfer 8809 KB
Theoretical minimum 8573 KB
Potential savings 235 KB (0.07g 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.

Send Feedback