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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
70
GRADE
C
FIX
2
REVIEW
1
PASS
3
INFO
0
Device:
Mobile Desktop
Checks
6
3 PASS 1 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::
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

D
Transfer Efficiency
Action
55% efficient
FIX
55% efficient
Warning::
Transfer efficiency: 55%
An estimated 479 KB (45%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 479 KB of unused JavaScript. This wasted data produces 0.13g of unnecessary CO2 per page view.
55% efficient

Total waste: 479 KB (45% of page weight)

Unused JS 479 KB

0.13g unnecessary CO2 per visit

Actual transfer 1078 KB
Theoretical minimum 598 KB
Potential savings 479 KB (0.13g 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
0.30g CO2 per view
PASS
0.30g CO2 per view
Info::
0.30g CO2 per page view
This page transfers 1.1 MB, producing an estimated 0.30g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.06g, network 0.05g, end-user device 0.19g.
Got: 0.30g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 35.8 kg CO2/year
With 10,000 page views per month, this page would generate approximately 35.8 kg of CO2 annually — equivalent to charging 4473 smartphones.

0.30g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 81% of websites

Sustainable Web Design model v4 · Page size: 1.1 MB

Your site
0.30g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.06g
Network
0.05g
End-user device
0.19g
At 10,000 monthly views: Monthly: 3.0 kg · Annual: 35.8 kg · ≈ 4473 smartphone charges
A+
Repeat Visit Weight
100% cached
PASS
100% cached
Info::
100% reduction on repeat visits
Returning visitors download only 5 KB (vs 1078 KB first visit). 25 of 26 resources are served from browser cache, saving 0.30g CO2 per repeat visit.
Info::
Repeat visit: 0.00g CO2 (first visit: 0.30g)
First visit
1078 KB
Repeat visit
5 KB

100% reduction on repeat visits

Saving 0.30g CO2 per returning visitor

25 resources served from cache · 1 resources re-downloaded

A
Carbon Budget
19th percentile
PASS
19th percentile
Info::
0.30g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 81% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 19th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.30g

19th percentile

Cleaner than 81% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 50% cleaner ✓
vs Target 40% 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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