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https://www.der-betze-brennt.de

Sustainability

· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
78
GRADE
C
FIX
2
REVIEW
2
PASS
3
INFO
1
Checks
8
3 PASS 2 REVIEW 2 FIX
D
CO2 Per Page Load
Action
0.83g CO2 per view
FIX
0.83g CO2 per view
Info::
0.83g CO2 per page view
This page transfers 3.5 MB, producing an estimated 0.83g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.02g, network 0.17g, end-user device 0.64g.
Got: 0.83g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 99.6 kg CO2/year
With 10,000 page views per month, this page would generate approximately 99.6 kg of CO2 annually — equivalent to charging 12449 smartphones.
Info::
Green hosting reduces data center emissions

0.83g

Carbon Footprint per page view

Above sustainability target (0.50g)

Cleaner than 44% of websites

Sustainable Web Design model v4 · Page size: 3.5 MB

Your site
0.83g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.02g
Network
0.17g
End-user device
0.64g
At 10,000 monthly views: Monthly: 8.3 kg · Annual: 99.6 kg · ≈ 12449 smartphone charges
D
Carbon Budget
Action
56th percentile
FIX
56th percentile
Warning::
0.83g CO2 — above the median website (0.60g)
Heavier than an estimated 44% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 56th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.83g

56th percentile

Cleaner than 44% of websites

Above the median website

vs Median 38% more
vs Target 66% more
B
Transfer Efficiency
82% efficient
REVIEW
82% efficient
Info::
Transfer efficiency: 82%
An estimated 648 KB (18%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 648 KB of unused JavaScript. This wasted data produces 0.15g of unnecessary CO2 per page view.
82% efficient

Total waste: 648 KB (18% of page weight)

Unused JS 648 KB

0.15g unnecessary CO2 per visit

Actual transfer 3590 KB
Theoretical minimum 2942 KB
Potential savings 648 KB (0.15g CO2)

See Deep Analysis sections above for specific optimizations.

B
Web Font Weight Variants
No detectable Google Fonts weights
REVIEW
No detectable Google Fonts weights
Info::
No detectable Google Fonts weights
The analyzer detects font weights via Google Fonts URL parameters (~70% of font-using sites). Self-hosted fonts and non-Google CDN fonts aren't visible to URL-based detection. If you self-host fonts, manually audit how many @font-face weights you ship -- 2-3 weights per family is typically enough; 5+ is usually unused payload.
A+
Green Hosting
Green (both)
PASS
Green (both)
Info::
Both hosting and CDN use renewable energy
Got: Hosting: Cloudflare, CDN: Cloudflare
Info::
Cloudflare: Verified by the Green Web Foundation
Info::
Cloudflare: 100% renewable energy for global network since 2019
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 Hosting Green Hosted
Hosting CloudflareCDN Cloudflare

Cloudflare: Verified by the Green Web Foundation

Cloudflare: 100% renewable energy for global network since 2019

Based on known provider commitments. Verify at thegreenwebfoundation.org

A+
Repeat Visit Weight
100% cached
PASS
100% cached
Info::
100% reduction on repeat visits
Returning visitors download only 15 KB (vs 3590 KB first visit). 62 of 64 resources are served from browser cache, saving 0.83g CO2 per repeat visit.
Info::
Repeat visit: 0.00g CO2 (first visit: 0.83g)
First visit
3590 KB
Repeat visit
15 KB

100% reduction on repeat visits

Saving 0.83g CO2 per returning visitor

62 resources served from cache · 2 resources re-downloaded

A+
Green Hosting
Whether the site is served from green-energy infrastructure
PASS

Green Hosting

This site is hosted on green energy infrastructure

Provider: Cloudflare

Image Optimization
74 images, 1366 KB total, 750 KB wasted
INFO

Image Optimization Audit

Total Images

74

Total Size

1366 KB

Oversized

17

Wasted

750 KB

29 missing alt text 22 missing dimensions 39 missing lazy loading
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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