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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
1.40g CO2 per view
FIX
1.40g CO2 per view
Warning::
1.40g CO2 per page view
This page transfers 4.9 MB, producing an estimated 1.40g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.26g, network 0.24g, end-user device 0.90g.
Got: 1.40g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 168.0 kg CO2/year
With 10,000 page views per month, this page would generate approximately 168.0 kg of CO2 annually — equivalent to charging 21005 smartphones.

1.40g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 28% of websites

Sustainable Web Design model v4 · Page size: 4.9 MB

Your site
1.40g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.26g
Network
0.24g
End-user device
0.90g
At 10,000 monthly views: Monthly: 14.0 kg · Annual: 168.0 kg · ≈ 21005 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 Not identified✗CDN Varnish✗

Based on known provider commitments. Verify at thegreenwebfoundation.org

F
Carbon Budget
Action
72th percentile
FIX
72th percentile
Warning::
1.40g CO2 — above the median website (0.60g)
Heavier than an estimated 28% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 72th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

1.40g

72nd percentile

Cleaner than 28% of websites

✗ Above the median website

vs Median 133% more
vs Target 180% more
B
Transfer Efficiency
89% efficient
REVIEW
89% efficient
Info::
Transfer efficiency: 89%
An estimated 547 KB (11%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 547 KB of unused JavaScript. This wasted data produces 0.15g of unnecessary CO2 per page view.
89% efficient

Total waste: 547 KB (11% of page weight)

Unused JS 547 KB

0.15g unnecessary CO2 per visit

Actual transfer 5063 KB
Theoretical minimum 4515 KB
Potential savings 547 KB (0.15g 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
93% cached
PASS
93% cached
Info::
93% reduction on repeat visits
Returning visitors download only 346 KB (vs 5063 KB first visit). 94 of 96 resources are served from browser cache, saving 1.30g CO2 per repeat visit.
Info::
Repeat visit: 0.10g CO2 (first visit: 1.40g)
First visit
5063 KB
Repeat visit
346 KB

93% reduction on repeat visits

Saving 1.30g CO2 per returning visitor

94 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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