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Sustainability

· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
71
GRADE
C
FIX
3
REVIEW
2
PASS
2
INFO
1
Checks
8
2 PASS 2 REVIEW 3 FIX
D
CO2 Per Page Load
Action
0.97g CO2 per view
FIX
0.97g CO2 per view
Info::
0.97g CO2 per page view
This page transfers 3.4 MB, producing an estimated 0.97g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.18g, network 0.17g, end-user device 0.62g.
Got: 0.97g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 116.6 kg CO2/year
With 10,000 page views per month, this page would generate approximately 116.6 kg of CO2 annually — equivalent to charging 14580 smartphones.

0.97g

Carbon Footprint per page view

Above sustainability target (0.50g)

Cleaner than 40% of websites

Sustainable Web Design model v4 · Page size: 3.4 MB

Your site
0.97g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.18g
Network
0.17g
End-user device
0.62g
At 10,000 monthly views: Monthly: 9.7 kg · Annual: 116.6 kg · ≈ 14580 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::
Azure: Microsoft is carbon-negative; Azure renewable varies by region
Info::
Azure CDN: Inherits Azure regional renewable mix
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 AzureCDN Azure CDN

Azure: Microsoft is carbon-negative; Azure renewable varies by region

Azure CDN: Inherits Azure regional renewable mix

Based on known provider commitments. Verify at thegreenwebfoundation.org

D
Carbon Budget
Action
60th percentile
FIX
60th percentile
Warning::
0.97g CO2 — above the median website (0.60g)
Heavier than an estimated 40% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 60th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.97g

60th percentile

Cleaner than 40% of websites

Above the median website

vs Median 62% more
vs Target 94% more
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.
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 35 KB (vs 3514 KB first visit). 109 of 111 resources are served from browser cache, saving 0.96g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.97g)
First visit
3514 KB
Repeat visit
35 KB

99% reduction on repeat visits

Saving 0.96g CO2 per returning visitor

109 resources served from cache · 2 resources re-downloaded

A+
Transfer Efficiency
98% efficient
PASS
98% efficient
Info::
Transfer efficiency: 98%
Only 67 KB of potential savings identified. Your page is well-optimized for size.
98% efficient

Total waste: 67 KB (2% of page weight)

Unused JS 67 KB

0.02g unnecessary CO2 per visit

Actual transfer 3514 KB
Theoretical minimum 3447 KB
Potential savings 67 KB (0.02g CO2)

See Deep Analysis sections above for specific optimizations.

Image Optimization
34 images, 11 KB total, 4 KB wasted
INFO

Image Optimization Audit

Total Images

34

Total Size

11 KB

Oversized

1

Wasted

4 KB

1 missing alt text 34 missing dimensions 1 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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