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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
90
GRADE
A
FIX
0
REVIEW
1
PASS
5
INFO
0
Checks
65 PASS 1 REVIEW
BTransfer Efficiency89% efficientREVIEW
Transfer Efficiency
89% efficient
89% efficient
Info::
Transfer efficiency: 89%
An estimated 139 KB (11%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 139 KB of unused JavaScript. This wasted data produces 0.03g of unnecessary CO2 per page view.
Total waste: 139 KB (11% of page weight)
Unused JS 139 KB
0.03g unnecessary CO2 per visit
Actual transfer 1214 KB
Theoretical minimum 1075 KB
Potential savings 139 KB (0.03g CO2)
See Deep Analysis sections above for specific optimizations.
ACO2 Per Page Load0.28g CO2 per viewPASS
CO2 Per Page Load
0.28g CO2 per view
0.28g CO2 per view
Info::
0.28g CO2 per page view
This page transfers 1.2 MB, producing an estimated 0.28g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.01g, network 0.06g, end-user device 0.22g.
Got: 0.28g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 33.7 kg CO2/year
With 10,000 page views per month, this page would generate approximately 33.7 kg of CO2 annually — equivalent to charging 4211 smartphones.
Info::
Green hosting reduces data center emissions
0.28g
Carbon Footprint per page view
✓ Below sustainability target (0.50g)
Cleaner than 82% of websites
Sustainable Web Design model v4 · Page size: 1.2 MB
Your site
0.28g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.01g
Network
0.06g
End-user device
0.22g
At 10,000 monthly views: Monthly: 2.8 kg · Annual: 33.7 kg · ≈ 4211 smartphone charges
A+Green HostingGreen (both)PASS
Green Hosting
Green (both)
Green (both)
Info::
Both hosting and CDN use renewable energy
Got: Hosting: Next.js, CDN: Fastly
Info::
Next.js: Verified by the Green Web Foundation
Info::
Fastly: 100% renewable energy for edge network
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 Next.js✓CDN Fastly✓
Next.js: Verified by the Green Web Foundation
Fastly: 100% renewable energy for edge network
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 13 KB (vs 1214 KB first visit). 51 of 52 resources are served from browser cache, saving 0.28g CO2 per repeat visit.
Info::
Repeat visit: 0.00g CO2 (first visit: 0.28g)
First visit
1214 KB
Repeat visit
13 KB
99% reduction on repeat visits
Saving 0.28g CO2 per returning visitor
51 resources served from cache · 1 resources re-downloaded
ACarbon Budget18th percentilePASS
Carbon Budget
18th percentile
18th percentile
Info::
0.28g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 82% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 18th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
0.28g
18th percentile
Cleaner than 82% of websites
✓ Below the Web Sustainability Guidelines target
vs Median 53% cleaner ✓
vs Target 44% cleaner ✓
A+Green HostingWhether the site is served from green-energy infrastructurePASS
Green Hosting
Whether the site is served from green-energy infrastructure
Green Hosting
This site is hosted on green energy infrastructure
Provider: Axis12 Ltd
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.