https://heavy.com
Sustainability
· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
83
GRADE
B
FIX
0
REVIEW
3
PASS
3
INFO
0
Checks
63 PASS 3 REVIEW
BGreen HostingGreen (hosting)REVIEW
Green Hosting
Green (hosting)
Green (hosting)
Info::
Cloudflare uses renewable energy
Info::
Cloudflare: Verified by the Green Web Foundation
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 Cloudflare✓CDN Not identified✗
Cloudflare: Verified by the Green Web Foundation
Based on known provider commitments. Verify at thegreenwebfoundation.org
BCarbon Budget37th percentileREVIEW
Carbon Budget
37th percentile
37th percentile
Info::
0.48g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 63% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 37th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
0.48g
37th percentile
Cleaner than 63% of websites
✓ Below the Web Sustainability Guidelines target
vs Median 21% cleaner ✓
vs Target 5% cleaner ✓
BTransfer Efficiency79% efficientREVIEW
Transfer Efficiency
79% efficient
79% efficient
Info::
Transfer efficiency: 79%
An estimated 427 KB (21%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 427 KB of unused JavaScript. This wasted data produces 0.10g of unnecessary CO2 per page view.
Total waste: 427 KB (21% of page weight)
Unused JS 427 KB
0.10g unnecessary CO2 per visit
Actual transfer 2059 KB
Theoretical minimum 1631 KB
Potential savings 427 KB (0.10g CO2)
See Deep Analysis sections above for specific optimizations.
ACO2 Per Page Load0.48g CO2 per viewPASS
CO2 Per Page Load
0.48g CO2 per view
0.48g CO2 per view
Info::
0.48g CO2 per page view
This page transfers 2.0 MB, producing an estimated 0.48g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.01g, network 0.10g, end-user device 0.37g.
Got: 0.48g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 57.1 kg CO2/year
With 10,000 page views per month, this page would generate approximately 57.1 kg of CO2 annually — equivalent to charging 7140 smartphones.
Info::
Green hosting reduces data center emissions
0.48g
Carbon Footprint per page view
✓ Below sustainability target (0.50g)
Cleaner than 63% of websites
Sustainable Web Design model v4 · Page size: 2.0 MB
Your site
0.48g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.01g
Network
0.10g
End-user device
0.37g
At 10,000 monthly views: Monthly: 4.8 kg · Annual: 57.1 kg · ≈ 7140 smartphone charges
A+Repeat Visit Weight94% cachedPASS
Repeat Visit Weight
94% cached
94% cached
Info::
94% reduction on repeat visits
Returning visitors download only 126 KB (vs 2059 KB first visit). 222 of 246 resources are served from browser cache, saving 0.45g CO2 per repeat visit.
Info::
Repeat visit: 0.03g CO2 (first visit: 0.48g)
First visit
2059 KB
Repeat visit
126 KB
94% reduction on repeat visits
Saving 0.45g CO2 per returning visitor
222 resources served from cache · 24 resources re-downloaded
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: Cloudflare
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.