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https://www.railway.app

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
58
GRADE
D
FIX
2
REVIEW
1
PASS
3
INFO
0
Device:
Mobile Desktop
Checks
6
3 PASS 1 REVIEW 2 FIX
F
CO2 Per Page Load
Action
3.06g CO2 per view
FIX
3.06g CO2 per view
Critical::
3.06g CO2 per page view
This page transfers 12.9 MB, producing an estimated 3.06g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.08g, network 0.63g, end-user device 2.35g.
Got: 3.06g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 367.0 kg CO2/year
With 10,000 page views per month, this page would generate approximately 367.0 kg of CO2 annually — equivalent to charging 45872 smartphones.
Info::
Green hosting reduces data center emissions

3.06g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 5% of websites

Sustainable Web Design model v4 · Page size: 12.9 MB

Your site
3.06g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.08g
Network
0.63g
End-user device
2.35g
At 10,000 monthly views: Monthly: 30.6 kg · Annual: 367.0 kg · ≈ 45872 smartphone charges
F
Carbon Budget
Action
95th percentile
FIX
95th percentile
Warning::
3.06g CO2 — above the median website (0.60g)
Heavier than an estimated 5% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 95th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

3.06g

95th percentile

Cleaner than 5% of websites

✗ Above the median website

vs Median 410% more
vs Target 512% more
C
Transfer Efficiency
Action
66% efficient
REVIEW
66% efficient
Warning::
Transfer efficiency: 66%
An estimated 4460 KB (34%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 4460 KB of unused JavaScript. This wasted data produces 1.03g of unnecessary CO2 per page view.
66% efficient

Total waste: 4460 KB (34% of page weight)

Unused JS 4460 KB

1.03g unnecessary CO2 per visit

Actual transfer 13230 KB
Theoretical minimum 8770 KB
Potential savings 4460 KB (1.03g CO2)

See Deep Analysis sections above for specific optimizations.

A+
Green Hosting
Green (both)
PASS
Green (both)
Info::
Both hosting and CDN use renewable energy
Got: Hosting: Railway, CDN: Cloudflare
Info::
Railway: 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 Railway✓CDN Cloudflare✓

Railway: 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 Weight
98% cached
PASS
98% cached
Info::
98% reduction on repeat visits
Returning visitors download only 228 KB (vs 13230 KB first visit). 283 of 287 resources are served from browser cache, saving 3.01g CO2 per repeat visit.
Info::
Repeat visit: 0.05g CO2 (first visit: 3.06g)
First visit
13230 KB
Repeat visit
228 KB

98% reduction on repeat visits

Saving 3.01g CO2 per returning visitor

283 resources served from cache · 4 resources re-downloaded

A+
Green Hosting
Whether the site is served from green-energy infrastructure
PASS

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.

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