https://tocstudio.co
Sustainability
· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
81
GRADE
B
FIX
1
REVIEW
4
PASS
2
INFO
1
Checks
82 PASS 4 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
BCarbon Budget31th percentileREVIEW
Carbon Budget
31th percentile
31th percentile
Info::
0.41g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 69% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 31th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
0.41g
31st percentile
Cleaner than 69% of websites
✓ Below the Web Sustainability Guidelines target
vs Median 32% cleaner ✓
vs Target 18% cleaner ✓
BTransfer Efficiency85% efficientREVIEW
Transfer Efficiency
85% efficient
85% efficient
Info::
Transfer efficiency: 85%
An estimated 227 KB (15%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 227 KB of unused JavaScript. This wasted data produces 0.06g of unnecessary CO2 per page view.
Total waste: 227 KB (15% of page weight)
Unused JS 227 KB
0.06g unnecessary CO2 per visit
Actual transfer 1484 KB
Theoretical minimum 1256 KB
Potential savings 227 KB (0.06g 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
ACO2 Per Page Load0.41g CO2 per viewPASS
CO2 Per Page Load
0.41g CO2 per view
0.41g CO2 per view
Info::
0.41g CO2 per page view
This page transfers 1.4 MB, producing an estimated 0.41g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.08g, network 0.07g, end-user device 0.26g.
Got: 0.41g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 49.3 kg CO2/year
With 10,000 page views per month, this page would generate approximately 49.3 kg of CO2 annually — equivalent to charging 6157 smartphones.
0.41g
Carbon Footprint per page view
✓ Below sustainability target (0.50g)
Cleaner than 69% of websites
Sustainable Web Design model v4 · Page size: 1.4 MB
Your site
0.41g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.08g
Network
0.07g
End-user device
0.26g
At 10,000 monthly views: Monthly: 4.1 kg · Annual: 49.3 kg · ≈ 6157 smartphone charges
A+Repeat Visit Weight97% cachedPASS
Repeat Visit Weight
97% cached
97% cached
Info::
97% reduction on repeat visits
Returning visitors download only 46 KB (vs 1484 KB first visit). 98 of 99 resources are served from browser cache, saving 0.40g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.41g)
First visit
1484 KB
Repeat visit
46 KB
97% reduction on repeat visits
Saving 0.40g CO2 per returning visitor
98 resources served from cache · 1 resources re-downloaded
Image Optimization13 images, 243 KB total, 223 KB wastedINFO
Image Optimization
13 images, 243 KB total, 223 KB wasted
Image Optimization Audit
Total Images
13
Total Size
243 KB
Oversized
11
Wasted
223 KB
2 missing alt text 2 missing dimensions 12 missing lazy loading
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.