https://ielts.org
Sustainability
· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
76
GRADE
C
FIX
1
REVIEW
2
PASS
3
INFO
0
Checks
63 PASS 2 REVIEW 1 FIX
DCarbon BudgetAction52th percentileFIX
Carbon Budget
Action52th percentile
52th percentile
Warning::
0.70g CO2 — above the median website (0.60g)
Heavier than an estimated 48% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 52th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
0.70g
52nd percentile
Cleaner than 48% of websites
✗ Above the median website
vs Median 17% more
vs Target 41% more
BCO2 Per Page Load0.70g CO2 per viewREVIEW
CO2 Per Page Load
0.70g CO2 per view
0.70g CO2 per view
Info::
0.70g CO2 per page view
This page transfers 3.0 MB, producing an estimated 0.70g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.02g, network 0.15g, end-user device 0.54g.
Got: 0.70g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 84.3 kg CO2/year
With 10,000 page views per month, this page would generate approximately 84.3 kg of CO2 annually — equivalent to charging 10538 smartphones.
Info::
Green hosting reduces data center emissions
0.70g
Carbon Footprint per page view
✗ Above sustainability target (0.50g)
Cleaner than 48% of websites
Sustainable Web Design model v4 · Page size: 3.0 MB
Your site
0.70g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.02g
Network
0.15g
End-user device
0.54g
At 10,000 monthly views: Monthly: 7.0 kg · Annual: 84.3 kg · ≈ 10538 smartphone charges
CTransfer EfficiencyAction61% efficientREVIEW
Transfer Efficiency
Action61% efficient
61% efficient
Warning::
Transfer efficiency: 61%
An estimated 1193 KB (39%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 1193 KB of unused JavaScript. This wasted data produces 0.28g of unnecessary CO2 per page view.
Total waste: 1193 KB (39% of page weight)
Unused JS 1193 KB
0.28g unnecessary CO2 per visit
Actual transfer 3039 KB
Theoretical minimum 1846 KB
Potential savings 1193 KB (0.28g CO2)
See Deep Analysis sections above for specific optimizations.
A+Green HostingGreen (both)PASS
Green Hosting
Green (both)
Green (both)
Info::
Both hosting and CDN use renewable energy
Got: Hosting: Amazon Web Services, CDN: Cloudflare
Info::
Amazon Web Services: 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 Amazon Web Services✓CDN Cloudflare✓
Amazon Web Services: 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 Weight98% cachedPASS
Repeat Visit Weight
98% cached
98% cached
Info::
98% reduction on repeat visits
Returning visitors download only 73 KB (vs 3039 KB first visit). 51 of 53 resources are served from browser cache, saving 0.69g CO2 per repeat visit.
Info::
Repeat visit: 0.02g CO2 (first visit: 0.70g)
First visit
3039 KB
Repeat visit
73 KB
98% reduction on repeat visits
Saving 0.69g CO2 per returning visitor
51 resources served from cache · 2 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.