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https://reason.com

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
62
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
1.38g CO2 per view
FIX
1.38g CO2 per view
Warning::
1.38g CO2 per page view
This page transfers 4.9 MB, producing an estimated 1.38g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.25g, network 0.24g, end-user device 0.88g.
Got: 1.38g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 165.1 kg CO2/year
With 10,000 page views per month, this page would generate approximately 165.1 kg of CO2 annually — equivalent to charging 20642 smartphones.

1.38g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 28% of websites

Sustainable Web Design model v4 · Page size: 4.9 MB

Your site
1.38g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.25g
Network
0.24g
End-user device
0.88g
At 10,000 monthly views: Monthly: 13.8 kg · Annual: 165.1 kg · ≈ 20642 smartphone charges
D
Green Hosting
Action
Unknown
FIX
Unknown
Info::
Hosting provider could not be identified
Without knowing the provider, we cannot determine their energy sourcing. Check with your hosting provider about their renewable energy commitments.
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 HostingUnable to Determine
Hosting Not identified✗CDN Not identified✗

Based on known provider commitments. Verify at thegreenwebfoundation.org

F
Carbon Budget
Action
72th percentile
FIX
72th percentile
Warning::
1.38g CO2 — above the median website (0.60g)
Heavier than an estimated 28% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 72th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

1.38g

72nd percentile

Cleaner than 28% of websites

✗ Above the median website

vs Median 129% more
vs Target 175% more
B
Transfer Efficiency
77% efficient
REVIEW
77% efficient
Info::
Transfer efficiency: 77%
An estimated 1132 KB (23%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 1132 KB of unused JavaScript. This wasted data produces 0.31g of unnecessary CO2 per page view.
77% efficient

Total waste: 1132 KB (23% of page weight)

Unused JS 1132 KB

0.31g unnecessary CO2 per visit

Actual transfer 4975 KB
Theoretical minimum 3843 KB
Potential savings 1132 KB (0.31g 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
97% cached
PASS
97% cached
Info::
97% reduction on repeat visits
Returning visitors download only 127 KB (vs 4975 KB first visit). 149 of 153 resources are served from browser cache, saving 1.34g CO2 per repeat visit.
Info::
Repeat visit: 0.04g CO2 (first visit: 1.38g)
First visit
4975 KB
Repeat visit
127 KB

97% reduction on repeat visits

Saving 1.34g CO2 per returning visitor

149 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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