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https://claude.com

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
65
GRADE
D
FIX
3
REVIEW
1
PASS
2
INFO
0
Device:
Mobile Desktop
Checks
6
2 PASS 1 REVIEW 3 FIX
D
CO2 Per Page Load
Action
0.98g CO2 per view
FIX
0.98g CO2 per view
Info::
0.98g CO2 per page view
This page transfers 4.2 MB, producing an estimated 0.98g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.02g, network 0.20g, end-user device 0.76g.
Got: 0.98g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 118.2 kg CO2/year
With 10,000 page views per month, this page would generate approximately 118.2 kg of CO2 annually — equivalent to charging 14773 smartphones.
Info::
Green hosting reduces data center emissions

0.98g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 40% of websites

Sustainable Web Design model v4 · Page size: 4.2 MB

Your site
0.98g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.02g
Network
0.20g
End-user device
0.76g
At 10,000 monthly views: Monthly: 9.8 kg · Annual: 118.2 kg · ≈ 14773 smartphone charges
D
Carbon Budget
Action
60th percentile
FIX
60th percentile
Warning::
0.98g CO2 — above the median website (0.60g)
Heavier than an estimated 40% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 60th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.98g

60th percentile

Cleaner than 40% of websites

✗ Above the median website

vs Median 64% more
vs Target 97% more
D
Transfer Efficiency
Action
43% efficient
FIX
43% efficient
Critical::
Transfer efficiency: 43%
An estimated 2420 KB (57%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 2420 KB of unused JavaScript. This wasted data produces 0.56g of unnecessary CO2 per page view.
43% efficient

Total waste: 2420 KB (57% of page weight)

Unused JS 2420 KB

0.56g unnecessary CO2 per visit

Actual transfer 4260 KB
Theoretical minimum 1840 KB
Potential savings 2420 KB (0.56g 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
Green Hosting
Green (cdn)
PASS
Green (cdn)
Info::
Cloudflare CDN uses renewable energy
Since most traffic is served through the CDN, the majority of data transfer energy is renewable.
Info::
Cloudflare: 100% renewable energy for global network since 2019
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 Hosting✓ Green Hosted
Hosting Not identified✗CDN Cloudflare✓

Cloudflare: 100% renewable energy for global network since 2019

Based on known provider commitments. Verify at thegreenwebfoundation.org

A+
Repeat Visit Weight
91% cached
PASS
91% cached
Info::
91% reduction on repeat visits
Returning visitors download only 383 KB (vs 4260 KB first visit). 78 of 81 resources are served from browser cache, saving 0.90g CO2 per repeat visit.
Info::
Repeat visit: 0.09g CO2 (first visit: 0.98g)
First visit
4260 KB
Repeat visit
383 KB

91% reduction on repeat visits

Saving 0.90g CO2 per returning visitor

78 resources served from cache · 3 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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