https://sonarsource.com
Sustainability
· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
73
GRADE
C
FIX
1
REVIEW
3
PASS
2
INFO
0
Checks
62 PASS 3 REVIEW 1 FIX
DCarbon BudgetAction55th percentileFIX
Carbon Budget
Action55th percentile
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 56% more
BCO2 Per Page Load0.78g CO2 per viewREVIEW
CO2 Per Page Load
0.78g CO2 per view
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: 93.6 kg CO2/year
With 10,000 page views per month, this page would generate approximately 93.6 kg of CO2 annually — equivalent to charging 11703 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: 93.6 kg · ≈ 11703 smartphone charges
BTransfer Efficiency77% efficientREVIEW
Transfer Efficiency
77% efficient
77% efficient
Info::
Transfer efficiency: 77%
An estimated 763 KB (23%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 763 KB of unused JavaScript. This wasted data produces 0.18g of unnecessary CO2 per page view.
Total waste: 763 KB (23% of page weight)
Unused JS 763 KB
0.18g unnecessary CO2 per visit
Actual transfer 3375 KB
Theoretical minimum 2611 KB
Potential savings 763 KB (0.18g CO2)
See Deep Analysis sections above for specific optimizations.
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
ActionWhether the site is served from green-energy infrastructure
Green Hosting
No green hosting detected
AGreen HostingGreen (cdn)PASS
Green Hosting
Green (cdn)
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 Weight99% cachedPASS
Repeat Visit Weight
99% cached
99% cached
Info::
99% reduction on repeat visits
Returning visitors download only 46 KB (vs 3375 KB first visit). 172 of 173 resources are served from browser cache, saving 0.77g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.78g)
First visit
3375 KB
Repeat visit
46 KB
99% reduction on repeat visits
Saving 0.77g CO2 per returning visitor
172 resources served from cache · 1 resources re-downloaded
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.