https://core.ac.uk
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
0
PASS
4
INFO
0
Checks
64 PASS 2 FIX
FCO2 Per Page LoadAction1.82g CO2 per viewFIX
CO2 Per Page Load
Action1.82g CO2 per view
1.82g CO2 per view
Warning::
1.82g CO2 per page view
This page transfers 7.7 MB, producing an estimated 1.82g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.05g, network 0.38g, end-user device 1.40g.
Got: 1.82g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 218.6 kg CO2/year
With 10,000 page views per month, this page would generate approximately 218.6 kg of CO2 annually — equivalent to charging 27319 smartphones.
Info::
Green hosting reduces data center emissions
1.82g
Carbon Footprint per page view
✗ Above sustainability target (0.50g)
Cleaner than 16% of websites
Sustainable Web Design model v4 · Page size: 7.7 MB
Your site
1.82g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.05g
Network
0.38g
End-user device
1.40g
At 10,000 monthly views: Monthly: 18.2 kg · Annual: 218.6 kg · ≈ 27319 smartphone charges
FCarbon BudgetAction84th percentileFIX
Carbon Budget
Action84th percentile
84th percentile
Warning::
1.82g CO2 — above the median website (0.60g)
Heavier than an estimated 16% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 84th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
1.82g
84th percentile
Cleaner than 16% of websites
✗ Above the median website
vs Median 204% more
vs Target 264% more
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 Weight100% cachedPASS
Repeat Visit Weight
100% cached
100% cached
Info::
100% reduction on repeat visits
Returning visitors download only 23 KB (vs 7879 KB first visit). 89 of 90 resources are served from browser cache, saving 1.82g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 1.82g)
First visit
7879 KB
Repeat visit
23 KB
100% reduction on repeat visits
Saving 1.82g CO2 per returning visitor
89 resources served from cache · 1 resources re-downloaded
A+Transfer Efficiency99% efficientPASS
Transfer Efficiency
99% efficient
99% efficient
Info::
Transfer efficiency: 99%
Only 93 KB of potential savings identified. Your page is well-optimized for size.
Total waste: 93 KB (1% of page weight)
Unused JS 93 KB
0.02g unnecessary CO2 per visit
Actual transfer 7879 KB
Theoretical minimum 7786 KB
Potential savings 93 KB (0.02g CO2)
See Deep Analysis sections above for specific optimizations.
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.