https://nomicalc.com
Sustainability
· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
79
GRADE
C
FIX
1
REVIEW
4
PASS
2
INFO
1
Checks
82 PASS 4 REVIEW 1 FIX
DCarbon BudgetAction52th percentileFIX
Carbon Budget
Action52th percentile
52th percentile
Warning::
0.70g CO2 — above the median website (0.60g)
Heavier than an estimated 48% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 52th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
0.70g
52nd percentile
Cleaner than 48% of websites
✗ Above the median website
vs Median 17% more
vs Target 41% more
BCO2 Per Page Load0.70g CO2 per viewREVIEW
CO2 Per Page Load
0.70g CO2 per view
0.70g CO2 per view
Info::
0.70g CO2 per page view
This page transfers 3.0 MB, producing an estimated 0.70g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.02g, network 0.15g, end-user device 0.54g.
Got: 0.70g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 84.4 kg CO2/year
With 10,000 page views per month, this page would generate approximately 84.4 kg of CO2 annually — equivalent to charging 10550 smartphones.
Info::
Green hosting reduces data center emissions
0.70g
Carbon Footprint per page view
✗ Above sustainability target (0.50g)
Cleaner than 48% of websites
Sustainable Web Design model v4 · Page size: 3.0 MB
Your site
0.70g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.02g
Network
0.15g
End-user device
0.54g
At 10,000 monthly views: Monthly: 7.0 kg · Annual: 84.4 kg · ≈ 10550 smartphone charges
BTransfer Efficiency88% efficientREVIEW
Transfer Efficiency
88% efficient
88% efficient
Info::
Transfer efficiency: 88%
An estimated 380 KB (12%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 380 KB of unused JavaScript. This wasted data produces 0.09g of unnecessary CO2 per page view.
Total waste: 380 KB (12% of page weight)
Unused JS 380 KB
0.09g unnecessary CO2 per visit
Actual transfer 3042 KB
Theoretical minimum 2662 KB
Potential savings 380 KB (0.09g CO2)
See Deep Analysis sections above for specific optimizations.
BWeb Font Weight VariantsNo detectable Google Fonts weightsREVIEW
Web Font Weight Variants
No detectable Google Fonts weights
No detectable Google Fonts weights
Info::
No detectable Google Fonts weights
The analyzer detects font weights via Google Fonts URL parameters (~70% of font-using sites). Self-hosted fonts and non-Google CDN fonts aren't visible to URL-based detection. If you self-host fonts, manually audit how many @font-face weights you ship -- 2-3 weights per family is typically enough; 5+ is usually unused payload.
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::
Netlify CDN uses renewable energy
Since most traffic is served through the CDN, the majority of data transfer energy is renewable.
Info::
Netlify: Hosted on AWS/Google Cloud with renewable energy matching
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 Netlify✓
Netlify: Hosted on AWS/Google Cloud with renewable energy matching
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 2 KB (vs 3042 KB first visit). 12 of 13 resources are served from browser cache, saving 0.70g CO2 per repeat visit.
Info::
Repeat visit: 0.00g CO2 (first visit: 0.70g)
First visit
3042 KB
Repeat visit
2 KB
100% reduction on repeat visits
Saving 0.70g CO2 per returning visitor
12 resources served from cache · 1 resources re-downloaded
Image Optimization2 images, 97 KB total, 46 KB wastedINFO
Image Optimization
2 images, 97 KB total, 46 KB wasted
Image Optimization Audit
Total Images
2
Total Size
97 KB
Oversized
1
Wasted
46 KB
2 missing dimensions
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.