https://ucs.org
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
0
REVIEW
3
PASS
3
INFO
0
Checks
63 PASS 3 REVIEW
BCO2 Per Page Load0.54g CO2 per viewREVIEW
CO2 Per Page Load
0.54g CO2 per view
0.54g CO2 per view
Info::
0.54g CO2 per page view
This page transfers 2.3 MB, producing an estimated 0.54g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.01g, network 0.11g, end-user device 0.42g.
Got: 0.54g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 65.2 kg CO2/year
With 10,000 page views per month, this page would generate approximately 65.2 kg of CO2 annually — equivalent to charging 8145 smartphones.
Info::
Green hosting reduces data center emissions
0.54g
Carbon Footprint per page view
✗ Above sustainability target (0.50g)
Cleaner than 56% of websites
Sustainable Web Design model v4 · Page size: 2.3 MB
Your site
0.54g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.01g
Network
0.11g
End-user device
0.42g
At 10,000 monthly views: Monthly: 5.4 kg · Annual: 65.2 kg · ≈ 8145 smartphone charges
BCarbon Budget44th percentileREVIEW
Carbon Budget
44th percentile
44th percentile
Info::
0.54g CO2 — below the median website (0.60g)
Better than an estimated 56% of websites, but above the sustainability target of 0.50g. Reducing page weight would help reach the target.
Info::
Estimated 44th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
0.54g
44th percentile
Cleaner than 56% of websites
✗ Above the median website
vs Median 9% cleaner ✓
vs Target 9% more
CTransfer EfficiencyAction71% efficientREVIEW
Transfer Efficiency
Action71% efficient
71% efficient
Warning::
Transfer efficiency: 71%
An estimated 692 KB (29%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 692 KB of unused JavaScript. This wasted data produces 0.16g of unnecessary CO2 per page view.
Total waste: 692 KB (29% of page weight)
Unused JS 692 KB
0.16g unnecessary CO2 per visit
Actual transfer 2349 KB
Theoretical minimum 1656 KB
Potential savings 692 KB (0.16g 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: Platform.sh, CDN: Cloudflare
Info::
Platform.sh: 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 Platform.sh✓CDN Cloudflare✓
Platform.sh: 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 Weight99% cachedPASS
Repeat Visit Weight
99% cached
99% cached
Info::
99% reduction on repeat visits
Returning visitors download only 34 KB (vs 2349 KB first visit). 79 of 84 resources are served from browser cache, saving 0.53g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.54g)
First visit
2349 KB
Repeat visit
34 KB
99% reduction on repeat visits
Saving 0.53g CO2 per returning visitor
79 resources served from cache · 5 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.