https://coduf.com
Sustainability
· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
83
GRADE
B
FIX
1
REVIEW
3
PASS
3
INFO
1
Checks
83 PASS 3 REVIEW 1 FIX
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
CTransfer EfficiencyAction66% efficientREVIEW
Transfer Efficiency
Action66% efficient
66% efficient
Warning::
Transfer efficiency: 66%
An estimated 114 KB (34%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 114 KB of unused JavaScript. This wasted data produces 0.03g of unnecessary CO2 per page view.
Total waste: 114 KB (34% of page weight)
Unused JS 114 KB
0.03g unnecessary CO2 per visit
Actual transfer 332 KB
Theoretical minimum 218 KB
Potential savings 114 KB (0.03g 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+CO2 Per Page Load0.09g CO2 per viewPASS
CO2 Per Page Load
0.09g CO2 per view
0.09g CO2 per view
Info::
0.09g CO2 per page view
This page transfers 0.3 MB, producing an estimated 0.09g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.02g, network 0.02g, end-user device 0.06g.
Got: 0.09g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 11.0 kg CO2/year
With 10,000 page views per month, this page would generate approximately 11.0 kg of CO2 annually — equivalent to charging 1379 smartphones.
0.09g
Carbon Footprint per page view
✓ Below sustainability target (0.50g)
Cleaner than 90% of websites
Sustainable Web Design model v4 · Page size: 0.3 MB
Your site
0.09g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.02g
Network
0.02g
End-user device
0.06g
At 10,000 monthly views: Monthly: 0.9 kg · Annual: 11.0 kg · ≈ 1379 smartphone charges
A+Repeat Visit Weight97% cachedPASS
Repeat Visit Weight
97% cached
97% cached
Info::
97% reduction on repeat visits
Returning visitors download only 9 KB (vs 332 KB first visit). 22 of 23 resources are served from browser cache, saving 0.09g CO2 per repeat visit.
Info::
Repeat visit: 0.00g CO2 (first visit: 0.09g)
First visit
332 KB
Repeat visit
9 KB
97% reduction on repeat visits
Saving 0.09g CO2 per returning visitor
22 resources served from cache · 1 resources re-downloaded
A+Carbon Budget10th percentilePASS
Carbon Budget
10th percentile
10th percentile
Info::
0.09g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 90% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 10th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
0.09g
10th percentile
Cleaner than 90% of websites
✓ Below the Web Sustainability Guidelines target
vs Median 85% cleaner ✓
vs Target 82% cleaner ✓
Image Optimization22 images, 19 KB total, 0 KB wastedINFO
Image Optimization
22 images, 19 KB total, 0 KB wasted
Image Optimization Audit
Total Images
22
Total Size
19 KB
18 missing dimensions 11 missing lazy loading
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.