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https://cancer.org

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
60
GRADE
D
FIX
3
REVIEW
2
PASS
1
INFO
0
Device:
Mobile Desktop
Checks
6
1 PASS 2 REVIEW 3 FIX
D
CO2 Per Page Load
Action
1.12g CO2 per view
FIX
1.12g CO2 per view
Warning::
1.12g CO2 per page view
This page transfers 4.0 MB, producing an estimated 1.12g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.21g, network 0.19g, end-user device 0.72g.
Got: 1.12g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 134.5 kg CO2/year
With 10,000 page views per month, this page would generate approximately 134.5 kg of CO2 annually — equivalent to charging 16815 smartphones.

1.12g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 36% of websites

Sustainable Web Design model v4 · Page size: 4.0 MB

Your site
1.12g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.21g
Network
0.19g
End-user device
0.72g
At 10,000 monthly views: Monthly: 11.2 kg · Annual: 134.5 kg · ≈ 16815 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::
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 Not identified✗

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

Based on known provider commitments. Verify at thegreenwebfoundation.org

D
Carbon Budget
Action
64th percentile
FIX
64th percentile
Warning::
1.12g CO2 — above the median website (0.60g)
Heavier than an estimated 36% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 64th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

1.12g

64th percentile

Cleaner than 36% of websites

✗ Above the median website

vs Median 87% more
vs Target 124% more
C
Transfer Efficiency
Action
71% efficient
REVIEW
71% efficient
Warning::
Transfer efficiency: 71%
An estimated 1165 KB (29%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 1165 KB of unused JavaScript. This wasted data produces 0.32g of unnecessary CO2 per page view.
71% efficient

Total waste: 1165 KB (29% of page weight)

Unused JS 1165 KB

0.32g unnecessary CO2 per visit

Actual transfer 4053 KB
Theoretical minimum 2887 KB
Potential savings 1165 KB (0.32g 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 71 KB (vs 4053 KB first visit). 91 of 94 resources are served from browser cache, saving 1.10g CO2 per repeat visit.
Info::
Repeat visit: 0.02g CO2 (first visit: 1.12g)
First visit
4053 KB
Repeat visit
71 KB

98% reduction on repeat visits

Saving 1.10g CO2 per returning visitor

91 resources served from cache · 3 resources re-downloaded

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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