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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
4
REVIEW
1
PASS
1
INFO
0
Device:
Mobile Desktop
Checks
6
1 PASS 1 REVIEW 4 FIX
D
CO2 Per Page Load
Action
1.36g CO2 per view
FIX
1.36g CO2 per view
Warning::
1.36g CO2 per page view
This page transfers 4.8 MB, producing an estimated 1.36g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.25g, network 0.23g, end-user device 0.87g.
Got: 1.36g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 162.7 kg CO2/year
With 10,000 page views per month, this page would generate approximately 162.7 kg of CO2 annually — equivalent to charging 20336 smartphones.

1.36g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 29% of websites

Sustainable Web Design model v4 · Page size: 4.8 MB

Your site
1.36g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.25g
Network
0.23g
End-user device
0.87g
At 10,000 monthly views: Monthly: 13.6 kg · Annual: 162.7 kg · ≈ 20336 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 Next.js✗CDN Not identified✗

Based on known provider commitments. Verify at thegreenwebfoundation.org

F
Carbon Budget
Action
71th percentile
FIX
71th percentile
Warning::
1.36g CO2 — above the median website (0.60g)
Heavier than an estimated 29% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 71th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

1.36g

71st percentile

Cleaner than 29% of websites

✗ Above the median website

vs Median 126% more
vs Target 171% more
D
Transfer Efficiency
Action
59% efficient
FIX
59% efficient
Warning::
Transfer efficiency: 59%
An estimated 1989 KB (41%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 1989 KB of unused JavaScript. This wasted data produces 0.55g of unnecessary CO2 per page view.
59% efficient

Total waste: 1989 KB (41% of page weight)

Unused JS 1989 KB

0.55g unnecessary CO2 per visit

Actual transfer 4902 KB
Theoretical minimum 2912 KB
Potential savings 1989 KB (0.55g 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 67 KB (vs 4902 KB first visit). 90 of 92 resources are served from browser cache, saving 1.34g CO2 per repeat visit.
Info::
Repeat visit: 0.02g CO2 (first visit: 1.36g)
First visit
4902 KB
Repeat visit
67 KB

99% reduction on repeat visits

Saving 1.34g CO2 per returning visitor

90 resources served from cache · 2 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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