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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
1.16g CO2 per view
FIX
1.16g CO2 per view
Warning::
1.16g CO2 per page view
This page transfers 4.1 MB, producing an estimated 1.16g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.21g, network 0.20g, end-user device 0.74g.
Got: 1.16g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 139.2 kg CO2/year
With 10,000 page views per month, this page would generate approximately 139.2 kg of CO2 annually — equivalent to charging 17400 smartphones.

1.16g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 34% of websites

Sustainable Web Design model v4 · Page size: 4.1 MB

Your site
1.16g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.21g
Network
0.20g
End-user device
0.74g
At 10,000 monthly views: Monthly: 11.6 kg · Annual: 139.2 kg · ≈ 17400 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::
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 Express✗CDN Not identified✗

Based on known provider commitments. Verify at thegreenwebfoundation.org

D
Carbon Budget
Action
66th percentile
FIX
66th percentile
Warning::
1.16g CO2 — above the median website (0.60g)
Heavier than an estimated 34% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 66th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

1.16g

66th percentile

Cleaner than 34% of websites

✗ Above the median website

vs Median 93% more
vs Target 132% more
C
Transfer Efficiency
Action
73% efficient
REVIEW
73% efficient
Warning::
Transfer efficiency: 73%
An estimated 1124 KB (27%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 1124 KB of unused JavaScript. This wasted data produces 0.31g of unnecessary CO2 per page view.
73% efficient

Total waste: 1124 KB (27% of page weight)

Unused JS 1124 KB

0.31g unnecessary CO2 per visit

Actual transfer 4194 KB
Theoretical minimum 3069 KB
Potential savings 1124 KB (0.31g 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
96% cached
PASS
96% cached
Info::
96% reduction on repeat visits
Returning visitors download only 186 KB (vs 4194 KB first visit). 251 of 262 resources are served from browser cache, saving 1.11g CO2 per repeat visit.
Info::
Repeat visit: 0.05g CO2 (first visit: 1.16g)
First visit
4194 KB
Repeat visit
186 KB

96% reduction on repeat visits

Saving 1.11g CO2 per returning visitor

251 resources served from cache · 11 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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