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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
1.20g CO2 per view
FIX
1.20g CO2 per view
Warning::
1.20g CO2 per page view
This page transfers 4.2 MB, producing an estimated 1.20g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.22g, network 0.21g, end-user device 0.77g.
Got: 1.20g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 144.1 kg CO2/year
With 10,000 page views per month, this page would generate approximately 144.1 kg of CO2 annually — equivalent to charging 18008 smartphones.

1.20g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 33% of websites

Sustainable Web Design model v4 · Page size: 4.2 MB

Your site
1.20g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.22g
Network
0.21g
End-user device
0.77g
At 10,000 monthly views: Monthly: 12.0 kg · Annual: 144.1 kg · ≈ 18008 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 Amazon Web Services✗CDN Varnish✗

Based on known provider commitments. Verify at thegreenwebfoundation.org

D
Carbon Budget
Action
67th percentile
FIX
67th percentile
Warning::
1.20g CO2 — above the median website (0.60g)
Heavier than an estimated 33% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 67th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

1.20g

67th percentile

Cleaner than 33% of websites

✗ Above the median website

vs Median 100% more
vs Target 140% more
C
Transfer Efficiency
Action
74% efficient
REVIEW
74% efficient
Warning::
Transfer efficiency: 74%
An estimated 1145 KB (26%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 1145 KB of unused JavaScript. This wasted data produces 0.32g of unnecessary CO2 per page view.
74% efficient

Total waste: 1145 KB (26% of page weight)

Unused JS 1145 KB

0.32g unnecessary CO2 per visit

Actual transfer 4341 KB
Theoretical minimum 3195 KB
Potential savings 1145 KB (0.32g 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 26 KB (vs 4341 KB first visit). 206 of 212 resources are served from browser cache, saving 1.19g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 1.20g)
First visit
4341 KB
Repeat visit
26 KB

99% reduction on repeat visits

Saving 1.19g CO2 per returning visitor

206 resources served from cache · 6 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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