https://github.com
Sustainability
· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
68
GRADE
D
FIX
3
REVIEW
3
PASS
1
INFO
1
Checks
81 PASS 3 REVIEW 3 FIX
DCO2 Per Page LoadAction1.12g CO2 per viewFIX
CO2 Per Page Load
Action1.12g CO2 per view
1.12g CO2 per view
Warning::
1.12g CO2 per page view
This page transfers 3.9 MB, producing an estimated 1.12g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.21g, network 0.19g, end-user device 0.72g.
Got: 1.12g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 134.1 kg CO2/year
With 10,000 page views per month, this page would generate approximately 134.1 kg of CO2 annually — equivalent to charging 16762 smartphones.
1.12g
Carbon Footprint per page view
✗ Above sustainability target (0.50g)
Cleaner than 36% of websites
Sustainable Web Design model v4 · Page size: 3.9 MB
Your site
1.12g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.21g
Network
0.19g
End-user device
0.72g
At 10,000 monthly views: Monthly: 11.2 kg · Annual: 134.1 kg · ≈ 16762 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 Amazon Web Services✗CDN Not identified✗
Based on known provider commitments. Verify at thegreenwebfoundation.org
DCarbon BudgetAction64th percentileFIX
Carbon Budget
Action64th percentile
64th percentile
Warning::
1.12g CO2 — above the median website (0.60g)
Heavier than an estimated 36% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 64th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
1.12g
64th percentile
Cleaner than 36% of websites
✗ Above the median website
vs Median 86% more
vs Target 123% more
BTransfer Efficiency75% efficientREVIEW
Transfer Efficiency
75% efficient
75% efficient
Info::
Transfer efficiency: 75%
An estimated 998 KB (25%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 998 KB of unused JavaScript. This wasted data produces 0.28g of unnecessary CO2 per page view.
Total waste: 998 KB (25% of page weight)
Unused JS 998 KB
0.28g unnecessary CO2 per visit
Actual transfer 4040 KB
Theoretical minimum 3042 KB
Potential savings 998 KB (0.28g 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 Weight98% cachedPASS
Repeat Visit Weight
98% cached
98% cached
Info::
98% reduction on repeat visits
Returning visitors download only 95 KB (vs 4040 KB first visit). 121 of 122 resources are served from browser cache, saving 1.09g CO2 per repeat visit.
Info::
Repeat visit: 0.03g CO2 (first visit: 1.12g)
First visit
4040 KB
Repeat visit
95 KB
98% reduction on repeat visits
Saving 1.09g CO2 per returning visitor
121 resources served from cache · 1 resources re-downloaded
Image Optimization22 images, 294 KB total, 9 KB wastedINFO
Image Optimization
22 images, 294 KB total, 9 KB wasted
Image Optimization Audit
Total Images
22
Total Size
294 KB
Oversized
2
Wasted
9 KB
9 missing dimensions 9 missing lazy loading
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.