https://boston.com
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
2
REVIEW
1
PASS
3
INFO
0
Checks
63 PASS 1 REVIEW 2 FIX
FCO2 Per Page LoadAction1.57g CO2 per viewFIX
CO2 Per Page Load
Action1.57g CO2 per view
1.57g CO2 per view
Warning::
1.57g CO2 per page view
This page transfers 6.6 MB, producing an estimated 1.57g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.04g, network 0.32g, end-user device 1.21g.
Got: 1.57g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 188.6 kg CO2/year
With 10,000 page views per month, this page would generate approximately 188.6 kg of CO2 annually — equivalent to charging 23570 smartphones.
Info::
Green hosting reduces data center emissions
1.57g
Carbon Footprint per page view
✗ Above sustainability target (0.50g)
Cleaner than 23% of websites
Sustainable Web Design model v4 · Page size: 6.6 MB
Your site
1.57g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.04g
Network
0.32g
End-user device
1.21g
At 10,000 monthly views: Monthly: 15.7 kg · Annual: 188.6 kg · ≈ 23570 smartphone charges
FCarbon BudgetAction77th percentileFIX
Carbon Budget
Action77th percentile
77th percentile
Warning::
1.57g CO2 — above the median website (0.60g)
Heavier than an estimated 23% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 77th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
1.57g
77th percentile
Cleaner than 23% of websites
✗ Above the median website
vs Median 162% more
vs Target 214% more
BTransfer Efficiency86% efficientREVIEW
Transfer Efficiency
86% efficient
86% efficient
Info::
Transfer efficiency: 86%
An estimated 964 KB (14%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 964 KB of unused JavaScript. This wasted data produces 0.22g of unnecessary CO2 per page view.
Total waste: 964 KB (14% of page weight)
Unused JS 964 KB
0.22g unnecessary CO2 per visit
Actual transfer 6798 KB
Theoretical minimum 5834 KB
Potential savings 964 KB (0.22g 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 Weight98% cachedPASS
Repeat Visit Weight
98% cached
98% cached
Info::
98% reduction on repeat visits
Returning visitors download only 131 KB (vs 6798 KB first visit). 217 of 224 resources are served from browser cache, saving 1.54g CO2 per repeat visit.
Info::
Repeat visit: 0.03g CO2 (first visit: 1.57g)
First visit
6798 KB
Repeat visit
131 KB
98% reduction on repeat visits
Saving 1.54g CO2 per returning visitor
217 resources served from cache · 7 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.