https://paulalevyct.com
Sustainability
· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
61
GRADE
D
FIX
3
REVIEW
3
PASS
1
INFO
1
Checks
81 PASS 3 REVIEW 3 FIX
DGreen HostingActionNot greenFIX
Green Hosting
ActionNot green
Not green
Info::
No confirmed renewable energy commitment detected
Consider providers like Cloudflare, Google Cloud, or Vercel that match 100% of their energy use with renewables.
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 HostingNot Green Hosted
Hosting Apache HTTP Server✗CDN Not identified✗
Based on known provider commitments. Verify at thegreenwebfoundation.org
DCarbon BudgetAction51th percentileFIX
Carbon Budget
Action51th percentile
51th percentile
Warning::
0.66g CO2 — above the median website (0.60g)
Heavier than an estimated 49% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 51th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
0.66g
51st percentile
Cleaner than 49% of websites
✗ Above the median website
vs Median 9% more
vs Target 31% more
DTransfer EfficiencyAction59% efficientFIX
Transfer Efficiency
Action59% efficient
59% efficient
Warning::
Transfer efficiency: 59%
An estimated 963 KB (41%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 963 KB of unused JavaScript. This wasted data produces 0.27g of unnecessary CO2 per page view.
Total waste: 963 KB (41% of page weight)
Unused JS 963 KB
0.27g unnecessary CO2 per visit
Actual transfer 2371 KB
Theoretical minimum 1407 KB
Potential savings 963 KB (0.27g CO2)
See Deep Analysis sections above for specific optimizations.
BCO2 Per Page Load0.66g CO2 per viewREVIEW
CO2 Per Page Load
0.66g CO2 per view
0.66g CO2 per view
Info::
0.66g CO2 per page view
This page transfers 2.3 MB, producing an estimated 0.66g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.12g, network 0.11g, end-user device 0.42g.
Got: 0.66g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 78.7 kg CO2/year
With 10,000 page views per month, this page would generate approximately 78.7 kg of CO2 annually — equivalent to charging 9835 smartphones.
0.66g
Carbon Footprint per page view
✗ Above sustainability target (0.50g)
Cleaner than 49% of websites
Sustainable Web Design model v4 · Page size: 2.3 MB
Your site
0.66g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.12g
Network
0.11g
End-user device
0.42g
At 10,000 monthly views: Monthly: 6.6 kg · Annual: 78.7 kg · ≈ 9835 smartphone charges
CWeb Font Weight VariantsAction19 font weights loaded across 1 famil(y/ies)REVIEW
Web Font Weight Variants
Action19 font weights loaded across 1 famil(y/ies)
19 font weights loaded across 1 famil(y/ies)
Warning::
19 font weights loaded -- likely 100+ KB of unused payload
Loading 19 font weights typically transfers 200-400 KB just for fonts. Most pages legitimately use 2-3 weights (regular + bold, maybe medium). Audit which weights your stylesheet actually applies and trim the Google Fonts URL accordingly. Affected families: Roboto.
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
A+Repeat Visit Weight98% cachedPASS
Repeat Visit Weight
98% cached
98% cached
Info::
98% reduction on repeat visits
Returning visitors download only 42 KB (vs 2371 KB first visit). 48 of 49 resources are served from browser cache, saving 0.64g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.66g)
First visit
2371 KB
Repeat visit
42 KB
98% reduction on repeat visits
Saving 0.64g CO2 per returning visitor
48 resources served from cache · 1 resources re-downloaded
Image Optimization5 images, 21 KB total, 0 KB wastedINFO
Image Optimization
5 images, 21 KB total, 0 KB wasted
Image Optimization Audit
Total Images
5
Total Size
21 KB
4 missing lazy loading
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.