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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
84
GRADE
B
FIX
1
REVIEW
2
PASS
3
INFO
0
Device:
Mobile Desktop
Checks
6
3 PASS 2 REVIEW 1 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::
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

B
Transfer Efficiency
78% efficient
REVIEW
78% efficient
Info::
Transfer efficiency: 78%
An estimated 156 KB (22%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 156 KB of unused JavaScript. This wasted data produces 0.04g of unnecessary CO2 per page view.
78% efficient

Total waste: 156 KB (22% of page weight)

Unused JS 156 KB

0.04g unnecessary CO2 per visit

Actual transfer 727 KB
Theoretical minimum 570 KB
Potential savings 156 KB (0.04g 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
CO2 Per Page Load
0.20g CO2 per view
PASS
0.20g CO2 per view
Info::
0.20g CO2 per page view
This page transfers 0.7 MB, producing an estimated 0.20g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.04g, network 0.03g, end-user device 0.13g.
Got: 0.20g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 24.1 kg CO2/year
With 10,000 page views per month, this page would generate approximately 24.1 kg of CO2 annually — equivalent to charging 3016 smartphones.

0.20g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 90% of websites

Sustainable Web Design model v4 · Page size: 0.7 MB

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

Energy Breakdown

Data center
0.04g
Network
0.03g
End-user device
0.13g
At 10,000 monthly views: Monthly: 2.0 kg · Annual: 24.1 kg · ≈ 3016 smartphone charges
A+
Repeat Visit Weight
90% cached
PASS
90% cached
Info::
90% reduction on repeat visits
Returning visitors download only 70 KB (vs 727 KB first visit). 69 of 71 resources are served from browser cache, saving 0.18g CO2 per repeat visit.
Info::
Repeat visit: 0.02g CO2 (first visit: 0.20g)
First visit
727 KB
Repeat visit
70 KB

90% reduction on repeat visits

Saving 0.18g CO2 per returning visitor

69 resources served from cache · 2 resources re-downloaded

A+
Carbon Budget
10th percentile
PASS
10th percentile
Info::
0.20g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 90% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 10th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.20g

10th percentile

Cleaner than 90% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 66% cleaner ✓
vs Target 60% cleaner ✓
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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