https://blurb.com
Sustainability
· 6 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
2
PASS
3
INFO
0
Checks
63 PASS 2 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::
0.42g 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
0.42g
31st percentile
Cleaner than 69% of websites
✓ Below the Web Sustainability Guidelines target
vs Median 30% cleaner ✓
vs Target 16% cleaner ✓
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 Load0.42g CO2 per viewPASS
CO2 Per Page Load
0.42g CO2 per view
0.42g CO2 per view
Info::
0.42g CO2 per page view
This page transfers 1.5 MB, producing an estimated 0.42g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.08g, network 0.07g, end-user device 0.27g.
Got: 0.42g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 50.3 kg CO2/year
With 10,000 page views per month, this page would generate approximately 50.3 kg of CO2 annually — equivalent to charging 6281 smartphones.
0.42g
Carbon Footprint per page view
✓ Below sustainability target (0.50g)
Cleaner than 69% of websites
Sustainable Web Design model v4 · Page size: 1.5 MB
Your site
0.42g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.08g
Network
0.07g
End-user device
0.27g
At 10,000 monthly views: Monthly: 4.2 kg · Annual: 50.3 kg · ≈ 6281 smartphone charges
A+Repeat Visit Weight97% cachedPASS
Repeat Visit Weight
97% cached
97% cached
Info::
97% reduction on repeat visits
Returning visitors download only 39 KB (vs 1514 KB first visit). 119 of 121 resources are served from browser cache, saving 0.41g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.42g)
First visit
1514 KB
Repeat visit
39 KB
97% reduction on repeat visits
Saving 0.41g CO2 per returning visitor
119 resources served from cache · 2 resources re-downloaded
A+Transfer Efficiency91% efficientPASS
Transfer Efficiency
91% efficient
91% efficient
Info::
Transfer efficiency: 91%
Only 136 KB of potential savings identified. Your page is well-optimized for size.
Total waste: 136 KB (9% of page weight)
Unused JS 136 KB
0.04g unnecessary CO2 per visit
Actual transfer 1514 KB
Theoretical minimum 1377 KB
Potential savings 136 KB (0.04g CO2)
See Deep Analysis sections above for specific optimizations.
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.