https://worldcat.org
Sustainability
· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
72
GRADE
C
FIX
2
REVIEW
1
PASS
3
INFO
0
Checks
63 PASS 1 REVIEW 2 FIX
DCarbon BudgetAction51th percentileFIX
Carbon Budget
Action51th percentile
51th percentile
Warning::
0.65g CO2 — above the median website (0.60g)
Heavier than an estimated 49% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 51th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
0.65g
51st percentile
Cleaner than 49% of websites
✗ Above the median website
vs Median 8% more
vs Target 29% more
FTransfer EfficiencyAction17% efficientFIX
Transfer Efficiency
Action17% efficient
17% efficient
Critical::
Transfer efficiency: 17%
An estimated 2336 KB (83%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 2336 KB of unused JavaScript. This wasted data produces 0.54g of unnecessary CO2 per page view.
Total waste: 2336 KB (83% of page weight)
Unused JS 2336 KB
0.54g unnecessary CO2 per visit
Actual transfer 2800 KB
Theoretical minimum 464 KB
Potential savings 2336 KB (0.54g CO2)
See Deep Analysis sections above for specific optimizations.
BCO2 Per Page Load0.65g CO2 per viewREVIEW
CO2 Per Page Load
0.65g CO2 per view
0.65g CO2 per view
Info::
0.65g CO2 per page view
This page transfers 2.7 MB, producing an estimated 0.65g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.02g, network 0.13g, end-user device 0.50g.
Got: 0.65g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 77.7 kg CO2/year
With 10,000 page views per month, this page would generate approximately 77.7 kg of CO2 annually — equivalent to charging 9709 smartphones.
Info::
Green hosting reduces data center emissions
0.65g
Carbon Footprint per page view
✗ Above sustainability target (0.50g)
Cleaner than 49% of websites
Sustainable Web Design model v4 · Page size: 2.7 MB
Your site
0.65g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.02g
Network
0.13g
End-user device
0.50g
At 10,000 monthly views: Monthly: 6.5 kg · Annual: 77.7 kg · ≈ 9709 smartphone charges
A+Green HostingGreen (both)PASS
Green Hosting
Green (both)
Green (both)
Info::
Both hosting and CDN use renewable energy
Got: Hosting: Next.js, CDN: Cloudflare
Info::
Next.js: Verified by the Green Web Foundation
Info::
Cloudflare: 100% renewable energy for global network since 2019
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 Hosting✓ Green Hosted
Hosting Next.js✓CDN Cloudflare✓
Next.js: Verified by the Green Web Foundation
Cloudflare: 100% renewable energy for global network since 2019
Based on known provider commitments. Verify at thegreenwebfoundation.org
A+Repeat Visit Weight97% cachedPASS
Repeat Visit Weight
97% cached
97% cached
Info::
97% reduction on repeat visits
Returning visitors download only 94 KB (vs 2800 KB first visit). 179 of 180 resources are served from browser cache, saving 0.63g CO2 per repeat visit.
Info::
Repeat visit: 0.02g CO2 (first visit: 0.65g)
First visit
2800 KB
Repeat visit
94 KB
97% reduction on repeat visits
Saving 0.63g CO2 per returning visitor
179 resources served from cache · 1 resources re-downloaded
A+Green HostingWhether the site is served from green-energy infrastructurePASS
Green Hosting
Whether the site is served from green-energy infrastructure
Green Hosting
This site is hosted on green energy infrastructure
Provider: Cloudflare
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.