https://opencollective.com
Sustainability
· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
80
GRADE
B
FIX
2
REVIEW
1
PASS
3
INFO
0
Checks
63 PASS 1 REVIEW 2 FIX
DCO2 Per Page LoadAction0.80g CO2 per viewFIX
CO2 Per Page Load
Action0.80g CO2 per view
0.80g CO2 per view
Info::
0.80g CO2 per page view
This page transfers 3.4 MB, producing an estimated 0.80g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.02g, network 0.17g, end-user device 0.62g.
Got: 0.80g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 96.1 kg CO2/year
With 10,000 page views per month, this page would generate approximately 96.1 kg of CO2 annually — equivalent to charging 12010 smartphones.
Info::
Green hosting reduces data center emissions
0.80g
Carbon Footprint per page view
✗ Above sustainability target (0.50g)
Cleaner than 45% of websites
Sustainable Web Design model v4 · Page size: 3.4 MB
Your site
0.80g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.02g
Network
0.17g
End-user device
0.62g
At 10,000 monthly views: Monthly: 8.0 kg · Annual: 96.1 kg · ≈ 12010 smartphone charges
DCarbon BudgetAction55th percentileFIX
Carbon Budget
Action55th percentile
55th percentile
Warning::
0.80g 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
0.80g
55th percentile
Cleaner than 45% of websites
✗ Above the median website
vs Median 33% more
vs Target 60% more
BTransfer Efficiency83% efficientREVIEW
Transfer Efficiency
83% efficient
83% efficient
Info::
Transfer efficiency: 83%
An estimated 598 KB (17%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 598 KB of unused JavaScript. This wasted data produces 0.14g of unnecessary CO2 per page view.
Total waste: 598 KB (17% of page weight)
Unused JS 598 KB
0.14g unnecessary CO2 per visit
Actual transfer 3464 KB
Theoretical minimum 2865 KB
Potential savings 598 KB (0.14g CO2)
See Deep Analysis sections above for specific optimizations.
A+Green HostingGreen (both)PASS
Green Hosting
Green (both)
Green (both)
Info::
Both hosting and CDN use renewable energy
Got: Hosting: Amazon Web Services, CDN: Cloudflare
Info::
Amazon Web Services: Verified by the Green Web Foundation
Info::
Cloudflare: 100% renewable energy for global network since 2019
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 Amazon Web Services✓CDN Cloudflare✓
Amazon Web Services: Verified by the Green Web Foundation
Cloudflare: 100% renewable energy for global network since 2019
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 13 KB (vs 3464 KB first visit). 57 of 58 resources are served from browser cache, saving 0.80g CO2 per repeat visit.
Info::
Repeat visit: 0.00g CO2 (first visit: 0.80g)
First visit
3464 KB
Repeat visit
13 KB
100% reduction on repeat visits
Saving 0.80g CO2 per returning visitor
57 resources served from cache · 1 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.