https://britishmuseum.org
Sustainability
· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
69
GRADE
D
FIX
2
REVIEW
1
PASS
3
INFO
0
Checks
63 PASS 1 REVIEW 2 FIX
DCO2 Per Page LoadAction0.91g CO2 per viewFIX
CO2 Per Page Load
Action0.91g CO2 per view
0.91g CO2 per view
Info::
0.91g CO2 per page view
This page transfers 3.9 MB, producing an estimated 0.91g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.02g, network 0.19g, end-user device 0.70g.
Got: 0.91g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 109.5 kg CO2/year
With 10,000 page views per month, this page would generate approximately 109.5 kg of CO2 annually — equivalent to charging 13687 smartphones.
Info::
Green hosting reduces data center emissions
0.91g
Carbon Footprint per page view
✗ Above sustainability target (0.50g)
Cleaner than 42% of websites
Sustainable Web Design model v4 · Page size: 3.9 MB
Your site
0.91g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.02g
Network
0.19g
End-user device
0.70g
At 10,000 monthly views: Monthly: 9.1 kg · Annual: 109.5 kg · ≈ 13687 smartphone charges
DCarbon BudgetAction58th percentileFIX
Carbon Budget
Action58th percentile
58th percentile
Warning::
0.91g CO2 — above the median website (0.60g)
Heavier than an estimated 42% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 58th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
0.91g
58th percentile
Cleaner than 42% of websites
✗ Above the median website
vs Median 52% more
vs Target 82% more
BTransfer Efficiency85% efficientREVIEW
Transfer Efficiency
85% efficient
85% efficient
Info::
Transfer efficiency: 85%
An estimated 594 KB (15%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 594 KB of unused JavaScript. This wasted data produces 0.14g of unnecessary CO2 per page view.
Total waste: 594 KB (15% of page weight)
Unused JS 594 KB
0.14g unnecessary CO2 per visit
Actual transfer 3947 KB
Theoretical minimum 3353 KB
Potential savings 594 KB (0.14g 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 Weight99% cachedPASS
Repeat Visit Weight
99% cached
99% cached
Info::
99% reduction on repeat visits
Returning visitors download only 34 KB (vs 3947 KB first visit). 47 of 49 resources are served from browser cache, saving 0.90g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.91g)
First visit
3947 KB
Repeat visit
34 KB
99% reduction on repeat visits
Saving 0.90g CO2 per returning visitor
47 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.