http://wonk.sytes.net/76s/pratka2/2015.html
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 LoadAction3.40g CO2 per viewFIX
CO2 Per Page Load
Action3.40g CO2 per view
3.40g CO2 per view
Critical::
3.40g CO2 per page view
This page transfers 12.0 MB, producing an estimated 3.40g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.63g, network 0.59g, end-user device 2.18g.
Got: 3.40g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 408.4 kg CO2/year
With 10,000 page views per month, this page would generate approximately 408.4 kg of CO2 annually — equivalent to charging 51046 smartphones.
3.40g
Carbon Footprint per page view
✗ Above sustainability target (0.50g)
Cleaner than 5% of websites
Sustainable Web Design model v4 · Page size: 12.0 MB
Your site
3.40g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.63g
Network
0.59g
End-user device
2.18g
At 10,000 monthly views: Monthly: 34.0 kg · Annual: 408.4 kg · ≈ 51046 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 Apache HTTP Server✗CDN Not identified✗
Based on known provider commitments. Verify at thegreenwebfoundation.org
FCarbon BudgetAction95th percentileFIX
Carbon Budget
Action95th percentile
95th percentile
Warning::
3.40g 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
3.40g
95th percentile
Cleaner than 5% of websites
✗ Above the median website
vs Median 467% more
vs Target 581% 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 Weight99% cachedPASS
Repeat Visit Weight
99% cached
99% cached
Info::
99% reduction on repeat visits
Returning visitors download only 149 KB (vs 12305 KB first visit). 85 of 88 resources are served from browser cache, saving 3.36g CO2 per repeat visit.
Info::
Repeat visit: 0.04g CO2 (first visit: 3.40g)
First visit
12305 KB
Repeat visit
149 KB
99% reduction on repeat visits
Saving 3.36g CO2 per returning visitor
85 resources served from cache · 3 resources re-downloaded
A+Transfer Efficiency99% efficientPASS
Transfer Efficiency
99% efficient
99% efficient
Info::
Transfer efficiency: 99%
Only 70 KB of potential savings identified. Your page is well-optimized for size.
Total waste: 70 KB (1% of page weight)
Unused JS 70 KB
0.02g unnecessary CO2 per visit
Actual transfer 12305 KB
Theoretical minimum 12234 KB
Potential savings 70 KB (0.02g CO2)
See Deep Analysis sections above for specific optimizations.
Image Optimization49 images, 10984 KB total, 0 KB wastedINFO
Image Optimization
49 images, 10984 KB total, 0 KB wasted
Image Optimization Audit
Total Images
49
Total Size
10984 KB
49 missing alt text 49 missing dimensions 49 missing lazy loading
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.