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https://marvel.com

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
53
GRADE
F
FIX
3
REVIEW
2
PASS
1
INFO
0
Device:
Mobile Desktop
Checks
6
1 PASS 2 REVIEW 3 FIX
F
CO2 Per Page Load
Action
2.29g CO2 per view
FIX
2.29g CO2 per view
Critical::
2.29g CO2 per page view
This page transfers 8.1 MB, producing an estimated 2.29g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.42g, network 0.40g, end-user device 1.47g.
Got: 2.29g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 274.8 kg CO2/year
With 10,000 page views per month, this page would generate approximately 274.8 kg of CO2 annually — equivalent to charging 34348 smartphones.

2.29g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 5% of websites

Sustainable Web Design model v4 · Page size: 8.1 MB

Your site
2.29g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.42g
Network
0.40g
End-user device
1.47g
At 10,000 monthly views: Monthly: 22.9 kg · Annual: 274.8 kg · ≈ 34348 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

F
Carbon Budget
Action
95th percentile
FIX
95th percentile
Warning::
2.29g 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

2.29g

95th percentile

Cleaner than 5% of websites

✗ Above the median website

vs Median 282% more
vs Target 358% more
B
Transfer Efficiency
89% efficient
REVIEW
89% efficient
Info::
Transfer efficiency: 89%
An estimated 936 KB (11%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 936 KB of unused JavaScript. This wasted data produces 0.26g of unnecessary CO2 per page view.
89% efficient

Total waste: 936 KB (11% of page weight)

Unused JS 936 KB

0.26g unnecessary CO2 per visit

Actual transfer 8279 KB
Theoretical minimum 7343 KB
Potential savings 936 KB (0.26g 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
91% cached
PASS
91% cached
Info::
91% reduction on repeat visits
Returning visitors download only 751 KB (vs 8279 KB first visit). 163 of 167 resources are served from browser cache, saving 2.08g CO2 per repeat visit.
Info::
Repeat visit: 0.21g CO2 (first visit: 2.29g)
First visit
8279 KB
Repeat visit
751 KB

91% reduction on repeat visits

Saving 2.08g CO2 per returning visitor

163 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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