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https://thetrainline.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
Checks
6
1 PASS 2 REVIEW 3 FIX
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 AWSCDN 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
51th percentile
FIX
51th percentile
Warning::
0.66g CO2 — above the median website (0.60g)
Heavier than an estimated 49% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 51th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.66g

51st percentile

Cleaner than 49% of websites

Above the median website

vs Median 9% more
vs Target 31% more
D
Transfer Efficiency
Action
58% efficient
FIX
58% efficient
Warning::
Transfer efficiency: 58%
An estimated 998 KB (42%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 998 KB of unused JavaScript. This wasted data produces 0.28g of unnecessary CO2 per page view.
58% efficient

Total waste: 998 KB (42% of page weight)

Unused JS 998 KB

0.28g unnecessary CO2 per visit

Actual transfer 2374 KB
Theoretical minimum 1376 KB
Potential savings 998 KB (0.28g CO2)

See Deep Analysis sections above for specific optimizations.

B
CO2 Per Page Load
0.66g CO2 per view
REVIEW
0.66g CO2 per view
Info::
0.66g CO2 per page view
This page transfers 2.3 MB, producing an estimated 0.66g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.12g, network 0.11g, end-user device 0.42g.
Got: 0.66g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 78.8 kg CO2/year
With 10,000 page views per month, this page would generate approximately 78.8 kg of CO2 annually — equivalent to charging 9851 smartphones.

0.66g

Carbon Footprint per page view

Above sustainability target (0.50g)

Cleaner than 49% of websites

Sustainable Web Design model v4 · Page size: 2.3 MB

Your site
0.66g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.12g
Network
0.11g
End-user device
0.42g
At 10,000 monthly views: Monthly: 6.6 kg · Annual: 78.8 kg · ≈ 9851 smartphone charges
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A+
Repeat Visit Weight
95% cached
PASS
95% cached
Info::
95% reduction on repeat visits
Returning visitors download only 123 KB (vs 2374 KB first visit). 75 of 77 resources are served from browser cache, saving 0.62g CO2 per repeat visit.
Info::
Repeat visit: 0.03g CO2 (first visit: 0.66g)
First visit
2374 KB
Repeat visit
123 KB

95% reduction on repeat visits

Saving 0.62g CO2 per returning visitor

75 resources served from cache · 2 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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