https://allbirds.com
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 LoadAction1.98g CO2 per viewFIX
CO2 Per Page Load
Action1.98g CO2 per view
1.98g CO2 per view
Warning::
1.98g CO2 per page view
This page transfers 8.4 MB, producing an estimated 1.98g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.05g, network 0.41g, end-user device 1.52g.
Got: 1.98g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 237.8 kg CO2/year
With 10,000 page views per month, this page would generate approximately 237.8 kg of CO2 annually — equivalent to charging 29730 smartphones.
Info::
Green hosting reduces data center emissions
1.98g
Carbon Footprint per page view
✗ Above sustainability target (0.50g)
Cleaner than 11% of websites
Sustainable Web Design model v4 · Page size: 8.4 MB
Your site
1.98g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.05g
Network
0.41g
End-user device
1.52g
At 10,000 monthly views: Monthly: 19.8 kg · Annual: 237.8 kg · ≈ 29730 smartphone charges
FCarbon BudgetAction89th percentileFIX
Carbon Budget
Action89th percentile
89th percentile
Warning::
1.98g CO2 — above the median website (0.60g)
Heavier than an estimated 11% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 89th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
1.98g
89th percentile
Cleaner than 11% of websites
✗ Above the median website
vs Median 230% more
vs Target 296% more
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 Weight97% cachedPASS
Repeat Visit Weight
97% cached
97% cached
Info::
97% reduction on repeat visits
Returning visitors download only 299 KB (vs 8575 KB first visit). 305 of 312 resources are served from browser cache, saving 1.91g CO2 per repeat visit.
Info::
Repeat visit: 0.07g CO2 (first visit: 1.98g)
First visit
8575 KB
Repeat visit
299 KB
97% reduction on repeat visits
Saving 1.91g CO2 per returning visitor
305 resources served from cache · 7 resources re-downloaded
A+Transfer Efficiency92% efficientPASS
Transfer Efficiency
92% efficient
92% efficient
Info::
Transfer efficiency: 92%
Only 721 KB of potential savings identified. Your page is well-optimized for size.
Total waste: 721 KB (8% of page weight)
Unused JS 721 KB
0.17g unnecessary CO2 per visit
Actual transfer 8575 KB
Theoretical minimum 7854 KB
Potential savings 721 KB (0.17g 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.