https://www.jcl.energy
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
5
PASS
1
INFO
1
Checks
81 PASS 5 REVIEW 1 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::
AWS: Renewable energy varies by region; committed to 100% by 2025
Info::
AWS CloudFront: Renewable varies by edge location
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 AWS✗CDN AWS CloudFront✗
AWS: Renewable energy varies by region; committed to 100% by 2025
AWS CloudFront: Renewable varies by edge location
Based on known provider commitments. Verify at thegreenwebfoundation.org
BCO2 Per Page Load0.59g CO2 per viewREVIEW
CO2 Per Page Load
0.59g CO2 per view
0.59g CO2 per view
Info::
0.59g CO2 per page view
This page transfers 2.1 MB, producing an estimated 0.59g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.11g, network 0.10g, end-user device 0.38g.
Got: 0.59g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 70.9 kg CO2/year
With 10,000 page views per month, this page would generate approximately 70.9 kg of CO2 annually — equivalent to charging 8858 smartphones.
0.59g
Carbon Footprint per page view
✗ Above sustainability target (0.50g)
Cleaner than 51% of websites
Sustainable Web Design model v4 · Page size: 2.1 MB
Your site
0.59g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.11g
Network
0.10g
End-user device
0.38g
At 10,000 monthly views: Monthly: 5.9 kg · Annual: 70.9 kg · ≈ 8858 smartphone charges
BCarbon Budget49th percentileREVIEW
Carbon Budget
49th percentile
49th percentile
Info::
0.59g CO2 — below the median website (0.60g)
Better than an estimated 51% of websites, but above the sustainability target of 0.50g. Reducing page weight would help reach the target.
Info::
Estimated 49th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
0.59g
49th percentile
Cleaner than 51% of websites
✗ Above the median website
vs Median 2% cleaner ✓
vs Target 18% more
BTransfer Efficiency84% efficientREVIEW
Transfer Efficiency
84% efficient
84% efficient
Info::
Transfer efficiency: 84%
An estimated 345 KB (16%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 345 KB of unused JavaScript. This wasted data produces 0.10g of unnecessary CO2 per page view.
Total waste: 345 KB (16% of page weight)
Unused JS 345 KB
0.10g unnecessary CO2 per visit
Actual transfer 2135 KB
Theoretical minimum 1789 KB
Potential savings 345 KB (0.10g 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 22 KB (vs 2135 KB first visit). 60 of 61 resources are served from browser cache, saving 0.58g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.59g)
First visit
2135 KB
Repeat visit
22 KB
99% reduction on repeat visits
Saving 0.58g CO2 per returning visitor
60 resources served from cache · 1 resources re-downloaded
Image Optimization15 images, 501 KB total, 363 KB wastedINFO
Image Optimization
15 images, 501 KB total, 363 KB wasted
Image Optimization Audit
Total Images
15
Total Size
501 KB
Oversized
3
Wasted
363 KB
4 missing dimensions 7 missing lazy loading
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.