https://www.sixgearengineering.com
Sustainability
· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
70
GRADE
C
FIX
3
REVIEW
3
PASS
1
INFO
1
Checks
81 PASS 3 REVIEW 3 FIX
DCO2 Per Page LoadAction1.19g CO2 per viewFIX
CO2 Per Page Load
Action1.19g CO2 per view
1.19g CO2 per view
Warning::
1.19g CO2 per page view
This page transfers 4.2 MB, producing an estimated 1.19g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.22g, network 0.21g, end-user device 0.76g.
Got: 1.19g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 142.5 kg CO2/year
With 10,000 page views per month, this page would generate approximately 142.5 kg of CO2 annually — equivalent to charging 17818 smartphones.
1.19g
Carbon Footprint per page view
✗ Above sustainability target (0.50g)
Cleaner than 34% of websites
Sustainable Web Design model v4 · Page size: 4.2 MB
Your site
1.19g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.22g
Network
0.21g
End-user device
0.76g
At 10,000 monthly views: Monthly: 11.9 kg · Annual: 142.5 kg · ≈ 17818 smartphone charges
DGreen HostingActionUnknownFIX
Green Hosting
ActionUnknown
Unknown
Info::
Hosting provider could not be identified
Without knowing the provider, we cannot determine their energy sourcing. Check with your hosting provider about their renewable energy commitments.
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 HostingUnable to Determine
Hosting Not identified✗CDN Not identified✗
Based on known provider commitments. Verify at thegreenwebfoundation.org
DCarbon BudgetAction66th percentileFIX
Carbon Budget
Action66th percentile
66th percentile
Warning::
1.19g CO2 — above the median website (0.60g)
Heavier than an estimated 34% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 66th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
1.19g
66th percentile
Cleaner than 34% of websites
✗ Above the median website
vs Median 98% more
vs Target 138% more
BTransfer Efficiency90% efficientREVIEW
Transfer Efficiency
90% efficient
90% efficient
Info::
Transfer efficiency: 90%
An estimated 445 KB (10%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 445 KB of unused JavaScript. This wasted data produces 0.12g of unnecessary CO2 per page view.
Total waste: 445 KB (10% of page weight)
Unused JS 445 KB
0.12g unnecessary CO2 per visit
Actual transfer 4295 KB
Theoretical minimum 3850 KB
Potential savings 445 KB (0.12g 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
A+Repeat Visit Weight99% cachedPASS
Repeat Visit Weight
99% cached
99% cached
Info::
99% reduction on repeat visits
Returning visitors download only 60 KB (vs 4295 KB first visit). 111 of 113 resources are served from browser cache, saving 1.17g CO2 per repeat visit.
Info::
Repeat visit: 0.02g CO2 (first visit: 1.19g)
First visit
4295 KB
Repeat visit
60 KB
99% reduction on repeat visits
Saving 1.17g CO2 per returning visitor
111 resources served from cache · 2 resources re-downloaded
Image Optimization98 images, 0 KB total, 0 KB wastedINFO
Image Optimization
98 images, 0 KB total, 0 KB wasted
Image Optimization Audit
Total Images
98
Total Size
0 KB
3 missing alt text 94 missing dimensions 13 missing lazy loading
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.