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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
81
GRADE
B
FIX
1
REVIEW
2
PASS
3
INFO
0
Device:
Mobile Desktop
Checks
6
3 PASS 2 REVIEW 1 FIX
D
Carbon Budget
Action
55th percentile
FIX
55th percentile
Warning::
0.78g CO2 — above the median website (0.60g)
Heavier than an estimated 45% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 55th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.78g

55th percentile

Cleaner than 45% of websites

✗ Above the median website

vs Median 30% more
vs Target 55% more
B
CO2 Per Page Load
0.78g CO2 per view
REVIEW
0.78g CO2 per view
Info::
0.78g CO2 per page view
This page transfers 3.3 MB, producing an estimated 0.78g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.02g, network 0.16g, end-user device 0.60g.
Got: 0.78g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 93.3 kg CO2/year
With 10,000 page views per month, this page would generate approximately 93.3 kg of CO2 annually — equivalent to charging 11658 smartphones.
Info::
Green hosting reduces data center emissions

0.78g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 45% of websites

Sustainable Web Design model v4 · Page size: 3.3 MB

Your site
0.78g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.02g
Network
0.16g
End-user device
0.60g
At 10,000 monthly views: Monthly: 7.8 kg · Annual: 93.3 kg · ≈ 11658 smartphone charges
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::
Netlify CDN uses renewable energy
Since most traffic is served through the CDN, the majority of data transfer energy is renewable.
Info::
Netlify: Hosted on AWS/Google Cloud with renewable energy matching
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 Netlify✓

Netlify: Hosted on AWS/Google Cloud with renewable energy matching

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 299 KB (vs 3362 KB first visit). 73 of 76 resources are served from browser cache, saving 0.71g CO2 per repeat visit.
Info::
Repeat visit: 0.07g CO2 (first visit: 0.78g)
First visit
3362 KB
Repeat visit
299 KB

91% reduction on repeat visits

Saving 0.71g CO2 per returning visitor

73 resources served from cache · 3 resources re-downloaded

A+
Transfer Efficiency
95% efficient
PASS
95% efficient
Info::
Transfer efficiency: 95%
Only 155 KB of potential savings identified. Your page is well-optimized for size.
95% efficient

Total waste: 155 KB (5% of page weight)

Unused JS 155 KB

0.04g unnecessary CO2 per visit

Actual transfer 3362 KB
Theoretical minimum 3207 KB
Potential savings 155 KB (0.04g CO2)

See Deep Analysis sections above for specific optimizations.

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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