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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
1.44g CO2 per view
FIX
1.44g CO2 per view
Warning::
1.44g CO2 per page view
This page transfers 5.1 MB, producing an estimated 1.44g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.27g, network 0.25g, end-user device 0.92g.
Got: 1.44g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 172.3 kg CO2/year
With 10,000 page views per month, this page would generate approximately 172.3 kg of CO2 annually — equivalent to charging 21540 smartphones.

1.44g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 27% of websites

Sustainable Web Design model v4 · Page size: 5.1 MB

Your site
1.44g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.27g
Network
0.25g
End-user device
0.92g
At 10,000 monthly views: Monthly: 14.4 kg · Annual: 172.3 kg · ≈ 21540 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::
AWS: Renewable energy varies by region; committed to 100% by 2025
Info::
AWS CloudFront: Renewable varies by edge location
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 AWS✗CDN AWS CloudFront✗

AWS: Renewable energy varies by region; committed to 100% by 2025

AWS CloudFront: Renewable varies by edge location

Based on known provider commitments. Verify at thegreenwebfoundation.org

F
Carbon Budget
Action
73th percentile
FIX
73th percentile
Warning::
1.44g CO2 — above the median website (0.60g)
Heavier than an estimated 27% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 73th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

1.44g

73rd percentile

Cleaner than 27% of websites

✗ Above the median website

vs Median 139% more
vs Target 187% more
B
Transfer Efficiency
77% efficient
REVIEW
77% efficient
Info::
Transfer efficiency: 77%
An estimated 1180 KB (23%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 1180 KB of unused JavaScript. This wasted data produces 0.33g of unnecessary CO2 per page view.
77% efficient

Total waste: 1180 KB (23% of page weight)

Unused JS 1180 KB

0.33g unnecessary CO2 per visit

Actual transfer 5192 KB
Theoretical minimum 4011 KB
Potential savings 1180 KB (0.33g 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
99% cached
PASS
99% cached
Info::
99% reduction on repeat visits
Returning visitors download only 41 KB (vs 5192 KB first visit). 120 of 124 resources are served from browser cache, saving 1.42g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 1.44g)
First visit
5192 KB
Repeat visit
41 KB

99% reduction on repeat visits

Saving 1.42g CO2 per returning visitor

120 resources served from cache · 4 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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