https://ibiblio.org
Sustainability
· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
90
GRADE
A
FIX
1
REVIEW
1
PASS
4
INFO
0
Checks
64 PASS 1 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
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 Load0.13g CO2 per viewPASS
CO2 Per Page Load
0.13g CO2 per view
0.13g CO2 per view
Info::
0.13g CO2 per page view
This page transfers 0.5 MB, producing an estimated 0.13g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.02g, network 0.02g, end-user device 0.09g.
Got: 0.13g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 16.1 kg CO2/year
With 10,000 page views per month, this page would generate approximately 16.1 kg of CO2 annually — equivalent to charging 2013 smartphones.
0.13g
Carbon Footprint per page view
✓ Below sustainability target (0.50g)
Cleaner than 90% of websites
Sustainable Web Design model v4 · Page size: 0.5 MB
Your site
0.13g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.02g
Network
0.02g
End-user device
0.09g
At 10,000 monthly views: Monthly: 1.3 kg · Annual: 16.1 kg · ≈ 2013 smartphone charges
A+Repeat Visit Weight96% cachedPASS
Repeat Visit Weight
96% cached
96% cached
Info::
96% reduction on repeat visits
Returning visitors download only 19 KB (vs 485 KB first visit). 20 of 22 resources are served from browser cache, saving 0.13g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.13g)
First visit
485 KB
Repeat visit
19 KB
96% reduction on repeat visits
Saving 0.13g CO2 per returning visitor
20 resources served from cache · 2 resources re-downloaded
A+Carbon Budget10th percentilePASS
Carbon Budget
10th percentile
10th percentile
Info::
0.13g 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
0.13g
10th percentile
Cleaner than 90% of websites
✓ Below the Web Sustainability Guidelines target
vs Median 78% cleaner ✓
vs Target 73% cleaner ✓
A+Transfer Efficiency100% efficientPASS
Transfer Efficiency
100% efficient
100% efficient
Info::
Transfer efficiency: 100%
Only 0 KB of potential savings identified. Your page is well-optimized for size.
Actual transfer 485 KB
Theoretical minimum 485 KB
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.