https://www.thepassivepractice.com
Sustainability
· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
60
GRADE
D
FIX
3
REVIEW
2
PASS
2
INFO
1
Checks
82 PASS 2 REVIEW 3 FIX
FCO2 Per Page LoadAction8.22g CO2 per viewFIX
CO2 Per Page Load
Action8.22g CO2 per view
8.22g CO2 per view
Critical::
8.22g CO2 per page view
This page transfers 29.0 MB, producing an estimated 8.22g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 1.52g, network 1.42g, end-user device 5.28g.
Got: 8.22g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 986.3 kg CO2/year
With 10,000 page views per month, this page would generate approximately 986.3 kg of CO2 annually — equivalent to charging 123290 smartphones.
8.22g
Carbon Footprint per page view
✗ Above sustainability target (0.50g)
Cleaner than 5% of websites
Sustainable Web Design model v4 · Page size: 29.0 MB
Your site
8.22g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
1.52g
Network
1.42g
End-user device
5.28g
At 10,000 monthly views: Monthly: 82.2 kg · Annual: 986.3 kg · ≈ 123290 smartphone charges
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 Not identified✗CDN Squarespace✗
Based on known provider commitments. Verify at thegreenwebfoundation.org
FCarbon BudgetAction95th percentileFIX
Carbon Budget
Action95th percentile
95th percentile
Warning::
8.22g CO2 — above the median website (0.60g)
Heavier than an estimated 5% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 95th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
8.22g
95th percentile
Cleaner than 5% of websites
✗ Above the median website
vs Median 1270% more
vs Target 1544% more
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
A+Repeat Visit Weight100% cachedPASS
Repeat Visit Weight
100% cached
100% cached
Info::
100% reduction on repeat visits
Returning visitors download only 92 KB (vs 29719 KB first visit). 131 of 132 resources are served from browser cache, saving 8.19g CO2 per repeat visit.
Info::
Repeat visit: 0.03g CO2 (first visit: 8.22g)
First visit
29719 KB
Repeat visit
92 KB
100% reduction on repeat visits
Saving 8.19g CO2 per returning visitor
131 resources served from cache · 1 resources re-downloaded
A+Transfer Efficiency99% efficientPASS
Transfer Efficiency
99% efficient
99% efficient
Info::
Transfer efficiency: 99%
Only 440 KB of potential savings identified. Your page is well-optimized for size.
Total waste: 440 KB (1% of page weight)
Unused JS 440 KB
0.12g unnecessary CO2 per visit
Actual transfer 29719 KB
Theoretical minimum 29278 KB
Potential savings 440 KB (0.12g CO2)
See Deep Analysis sections above for specific optimizations.
Image Optimization80 images, 1468 KB total, 155 KB wastedINFO
Image Optimization
80 images, 1468 KB total, 155 KB wasted
Image Optimization Audit
Total Images
80
Total Size
1468 KB
Oversized
1
Wasted
155 KB
5 missing dimensions 6 missing lazy loading
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.