https://www.eff.org
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
0
REVIEW
4
PASS
2
INFO
0
Checks
62 PASS 4 REVIEW
BCO2 Per Page Load0.63g CO2 per viewREVIEW
CO2 Per Page Load
0.63g CO2 per view
0.63g CO2 per view
Info::
0.63g CO2 per page view
This page transfers 2.7 MB, producing an estimated 0.63g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.02g, network 0.13g, end-user device 0.48g.
Got: 0.63g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 75.6 kg CO2/year
With 10,000 page views per month, this page would generate approximately 75.6 kg of CO2 annually — equivalent to charging 9446 smartphones.
Info::
Green hosting reduces data center emissions
0.63g
Carbon Footprint per page view
✗ Above sustainability target (0.50g)
Cleaner than 50% of websites
Sustainable Web Design model v4 · Page size: 2.7 MB
Your site
0.63g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.02g
Network
0.13g
End-user device
0.48g
At 10,000 monthly views: Monthly: 6.3 kg · Annual: 75.6 kg · ≈ 9446 smartphone charges
BCarbon Budget50th percentileREVIEW
Carbon Budget
50th percentile
50th percentile
Warning::
0.63g CO2 — above the median website (0.60g)
Heavier than an estimated 50% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 50th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
0.63g
50th percentile
Cleaner than 50% of websites
✗ Above the median website
vs Median 5% more
vs Target 26% more
BTransfer Efficiency82% efficientREVIEW
Transfer Efficiency
82% efficient
82% efficient
Info::
Transfer efficiency: 82%
An estimated 478 KB (18%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 478 KB of unused JavaScript. This wasted data produces 0.11g of unnecessary CO2 per page view.
Total waste: 478 KB (18% of page weight)
Unused JS 478 KB
0.11g unnecessary CO2 per visit
Actual transfer 2724 KB
Theoretical minimum 2245 KB
Potential savings 478 KB (0.11g 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::
Fastly CDN uses renewable energy
Since most traffic is served through the CDN, the majority of data transfer energy is renewable.
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 Not identified✗CDN Fastly✓
Fastly: 100% renewable energy for edge network
Based on known provider commitments. Verify at thegreenwebfoundation.org
A+Repeat Visit Weight100% cachedPASS
Repeat Visit Weight
100% cached
100% cached
Info::
100% reduction on repeat visits
Returning visitors download only 12 KB (vs 2724 KB first visit). 38 of 39 resources are served from browser cache, saving 0.63g CO2 per repeat visit.
Info::
Repeat visit: 0.00g CO2 (first visit: 0.63g)
First visit
2724 KB
Repeat visit
12 KB
100% reduction on repeat visits
Saving 0.63g CO2 per returning visitor
38 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.