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https://alltrails.com

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
64
GRADE
D
FIX
3
REVIEW
2
PASS
1
INFO
0
Device:
Mobile Desktop
Checks
6
1 PASS 2 REVIEW 3 FIX
D
CO2 Per Page Load
Action
1.01g CO2 per view
FIX
1.01g CO2 per view
Warning::
1.01g CO2 per page view
This page transfers 3.6 MB, producing an estimated 1.01g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.19g, network 0.18g, end-user device 0.65g.
Got: 1.01g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 121.6 kg CO2/year
With 10,000 page views per month, this page would generate approximately 121.6 kg of CO2 annually — equivalent to charging 15195 smartphones.

1.01g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 39% of websites

Sustainable Web Design model v4 · Page size: 3.6 MB

Your site
1.01g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.19g
Network
0.18g
End-user device
0.65g
At 10,000 monthly views: Monthly: 10.1 kg · Annual: 121.6 kg · ≈ 15195 smartphone charges
D
Green Hosting
Action
Not green
FIX
Not green
Info::
No confirmed renewable energy commitment detected
Consider providers like Cloudflare, Google Cloud, or Vercel that match 100% of their energy use with renewables.
Info::
AWS: Renewable energy varies by region; committed to 100% by 2025
Info::
AWS CloudFront: Renewable varies by edge location
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 HostingNot Green Hosted
Hosting AWS✗CDN AWS CloudFront✗

AWS: Renewable energy varies by region; committed to 100% by 2025

AWS CloudFront: Renewable varies by edge location

Based on known provider commitments. Verify at thegreenwebfoundation.org

D
Carbon Budget
Action
61th percentile
FIX
61th percentile
Warning::
1.01g CO2 — above the median website (0.60g)
Heavier than an estimated 39% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 61th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

1.01g

61st percentile

Cleaner than 39% of websites

✗ Above the median website

vs Median 69% more
vs Target 103% more
B
Transfer Efficiency
85% efficient
REVIEW
85% efficient
Info::
Transfer efficiency: 85%
An estimated 551 KB (15%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 551 KB of unused JavaScript. This wasted data produces 0.15g of unnecessary CO2 per page view.
85% efficient

Total waste: 551 KB (15% of page weight)

Unused JS 551 KB

0.15g unnecessary CO2 per visit

Actual transfer 3662 KB
Theoretical minimum 3111 KB
Potential savings 551 KB (0.15g CO2)

See Deep Analysis sections above for specific optimizations.

C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A+
Repeat Visit Weight
92% cached
PASS
92% cached
Info::
92% reduction on repeat visits
Returning visitors download only 284 KB (vs 3662 KB first visit). 131 of 135 resources are served from browser cache, saving 0.93g CO2 per repeat visit.
Info::
Repeat visit: 0.08g CO2 (first visit: 1.01g)
First visit
3662 KB
Repeat visit
284 KB

92% reduction on repeat visits

Saving 0.93g CO2 per returning visitor

131 resources served from cache · 4 resources re-downloaded

All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

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