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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
73
GRADE
C
FIX
2
REVIEW
3
PASS
2
INFO
1
Device:
Mobile Desktop
Checks
8
2 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::
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 Azure✗CDN 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
51th percentile
FIX
51th percentile
Warning::
0.64g CO2 — above the median website (0.60g)
Heavier than an estimated 49% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 51th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.64g

51st percentile

Cleaner than 49% of websites

✗ Above the median website

vs Median 7% more
vs Target 28% more
B
CO2 Per Page Load
0.64g CO2 per view
REVIEW
0.64g CO2 per view
Info::
0.64g CO2 per page view
This page transfers 2.3 MB, producing an estimated 0.64g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.12g, network 0.11g, end-user device 0.41g.
Got: 0.64g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 77.1 kg CO2/year
With 10,000 page views per month, this page would generate approximately 77.1 kg of CO2 annually — equivalent to charging 9635 smartphones.

0.64g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 49% of websites

Sustainable Web Design model v4 · Page size: 2.3 MB

Your site
0.64g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.12g
Network
0.11g
End-user device
0.41g
At 10,000 monthly views: Monthly: 6.4 kg · Annual: 77.1 kg · ≈ 9635 smartphone charges
B
Transfer Efficiency
87% efficient
REVIEW
87% efficient
Info::
Transfer efficiency: 87%
An estimated 310 KB (13%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 310 KB of unused JavaScript. This wasted data produces 0.09g of unnecessary CO2 per page view.
87% efficient

Total waste: 310 KB (13% of page weight)

Unused JS 310 KB

0.09g unnecessary CO2 per visit

Actual transfer 2322 KB
Theoretical minimum 2011 KB
Potential savings 310 KB (0.09g 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
98% cached
PASS
98% cached
Info::
98% reduction on repeat visits
Returning visitors download only 57 KB (vs 2322 KB first visit). 39 of 40 resources are served from browser cache, saving 0.63g CO2 per repeat visit.
Info::
Repeat visit: 0.02g CO2 (first visit: 0.64g)
First visit
2322 KB
Repeat visit
57 KB

98% reduction on repeat visits

Saving 0.63g CO2 per returning visitor

39 resources served from cache · 1 resources re-downloaded

A+
Web Font Weight Variants
3 font weights loaded across 1 famil(y/ies) -- reasonable
PASS
3 font weights loaded across 1 famil(y/ies) -- reasonable
Info::
3 font weight(s) loaded across 1 famil(y/ies)
Image Optimization
7 images, 750 KB total, 460 KB wasted
INFO

Image Optimization Audit

Total Images

7

Total Size

750 KB

Oversized

5

Wasted

460 KB

1 missing alt text 6 missing dimensions 5 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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