https://bhf.org.uk
Sustainability
· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
65
GRADE
D
FIX
2
REVIEW
1
PASS
3
INFO
0
Checks
63 PASS 1 REVIEW 2 FIX
FCO2 Per Page LoadAction2.17g CO2 per viewFIX
CO2 Per Page Load
Action2.17g CO2 per view
2.17g CO2 per view
Critical::
2.17g CO2 per page view
This page transfers 9.2 MB, producing an estimated 2.17g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.05g, network 0.45g, end-user device 1.67g.
Got: 2.17g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 260.6 kg CO2/year
With 10,000 page views per month, this page would generate approximately 260.6 kg of CO2 annually — equivalent to charging 32578 smartphones.
Info::
Green hosting reduces data center emissions
2.17g
Carbon Footprint per page view
✗ Above sustainability target (0.50g)
Cleaner than 5% of websites
Sustainable Web Design model v4 · Page size: 9.2 MB
Your site
2.17g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.05g
Network
0.45g
End-user device
1.67g
At 10,000 monthly views: Monthly: 21.7 kg · Annual: 260.6 kg · ≈ 32578 smartphone charges
FCarbon BudgetAction95th percentileFIX
Carbon Budget
Action95th percentile
95th percentile
Warning::
2.17g CO2 — above the median website (0.60g)
Heavier than an estimated 5% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 95th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
2.17g
95th percentile
Cleaner than 5% of websites
✗ Above the median website
vs Median 262% more
vs Target 334% more
BTransfer Efficiency89% efficientREVIEW
Transfer Efficiency
89% efficient
89% efficient
Info::
Transfer efficiency: 89%
An estimated 1032 KB (11%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 1032 KB of unused JavaScript. This wasted data produces 0.24g of unnecessary CO2 per page view.
Total waste: 1032 KB (11% of page weight)
Unused JS 1032 KB
0.24g unnecessary CO2 per visit
Actual transfer 9396 KB
Theoretical minimum 8363 KB
Potential savings 1032 KB (0.24g 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: Cloudflare, CDN: Cloudflare
Info::
Cloudflare: 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 Cloudflare✓CDN Cloudflare✓
Cloudflare: 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 27 KB (vs 9396 KB first visit). 51 of 52 resources are served from browser cache, saving 2.17g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 2.17g)
First visit
9396 KB
Repeat visit
27 KB
100% reduction on repeat visits
Saving 2.17g CO2 per returning visitor
51 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.