https://www.hightolowvoltage.com
Sustainability
· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
75
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::
0.68g 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
0.68g
52nd percentile
Cleaner than 48% of websites
✗ Above the median website
vs Median 13% more
vs Target 35% more
BCO2 Per Page Load0.68g CO2 per viewREVIEW
CO2 Per Page Load
0.68g CO2 per view
0.68g CO2 per view
Info::
0.68g CO2 per page view
This page transfers 2.9 MB, producing an estimated 0.68g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.02g, network 0.14g, end-user device 0.52g.
Got: 0.68g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 81.0 kg CO2/year
With 10,000 page views per month, this page would generate approximately 81.0 kg of CO2 annually — equivalent to charging 10128 smartphones.
Info::
Green hosting reduces data center emissions
0.68g
Carbon Footprint per page view
✗ Above sustainability target (0.50g)
Cleaner than 48% of websites
Sustainable Web Design model v4 · Page size: 2.9 MB
Your site
0.68g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.02g
Network
0.14g
End-user device
0.52g
At 10,000 monthly views: Monthly: 6.8 kg · Annual: 81.0 kg · ≈ 10128 smartphone charges
BTransfer Efficiency78% efficientREVIEW
Transfer Efficiency
78% efficient
78% efficient
Info::
Transfer efficiency: 78%
An estimated 638 KB (22%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 638 KB of unused JavaScript. This wasted data produces 0.15g of unnecessary CO2 per page view.
Total waste: 638 KB (22% of page weight)
Unused JS 638 KB
0.15g unnecessary CO2 per visit
Actual transfer 2921 KB
Theoretical minimum 2283 KB
Potential savings 638 KB (0.15g CO2)
See Deep Analysis sections above for specific optimizations.
CWeb Font Weight VariantsAction18 font weights loaded across 1 famil(y/ies)REVIEW
Web Font Weight Variants
Action18 font weights loaded across 1 famil(y/ies)
18 font weights loaded across 1 famil(y/ies)
Warning::
18 font weights loaded -- likely 100+ KB of unused payload
Loading 18 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: Montserrat.
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::
Cloudflare CDN uses renewable energy
Since most traffic is served through the CDN, the majority of data transfer energy is renewable.
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 Not identified✗CDN Cloudflare✓
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 16 KB (vs 2921 KB first visit). 118 of 121 resources are served from browser cache, saving 0.67g CO2 per repeat visit.
Info::
Repeat visit: 0.00g CO2 (first visit: 0.68g)
First visit
2921 KB
Repeat visit
16 KB
99% reduction on repeat visits
Saving 0.67g CO2 per returning visitor
118 resources served from cache · 3 resources re-downloaded
Image Optimization30 images, 0 KB total, 0 KB wastedINFO
Image Optimization
30 images, 0 KB total, 0 KB wasted
Image Optimization Audit
Total Images
30
Total Size
0 KB
Oversized
1
27 missing dimensions 3 missing lazy loading
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.