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https://vercel.com

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
77
GRADE
C
FIX
2
REVIEW
2
PASS
2
INFO
0
Device:
Mobile Desktop
Checks
6
2 PASS 2 REVIEW 2 FIX
D
CO2 Per Page Load
Action
1.07g CO2 per view
FIX
1.07g CO2 per view
Warning::
1.07g CO2 per page view
This page transfers 4.5 MB, producing an estimated 1.07g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.03g, network 0.22g, end-user device 0.82g.
Got: 1.07g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 128.6 kg CO2/year
With 10,000 page views per month, this page would generate approximately 128.6 kg of CO2 annually — equivalent to charging 16069 smartphones.
Info::
Green hosting reduces data center emissions

1.07g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 37% of websites

Sustainable Web Design model v4 · Page size: 4.5 MB

Your site
1.07g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.03g
Network
0.22g
End-user device
0.82g
At 10,000 monthly views: Monthly: 10.7 kg · Annual: 128.6 kg · ≈ 16069 smartphone charges
D
Carbon Budget
Action
63th percentile
FIX
63th percentile
Warning::
1.07g CO2 — above the median website (0.60g)
Heavier than an estimated 37% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 63th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

1.07g

63rd percentile

Cleaner than 37% of websites

✗ Above the median website

vs Median 79% more
vs Target 114% more
C
Transfer Efficiency
Action
62% efficient
REVIEW
62% efficient
Warning::
Transfer efficiency: 62%
An estimated 1753 KB (38%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 1753 KB of unused JavaScript. This wasted data produces 0.41g of unnecessary CO2 per page view.
62% efficient

Total waste: 1753 KB (38% of page weight)

Unused JS 1753 KB

0.41g unnecessary CO2 per visit

Actual transfer 4634 KB
Theoretical minimum 2881 KB
Potential savings 1753 KB (0.41g 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
Green Hosting
Green (cdn)
PASS
Green (cdn)
Info::
Vercel CDN uses renewable energy
Since most traffic is served through the CDN, the majority of data transfer energy is renewable.
Info::
Vercel: Hosted on AWS/Google Cloud with 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 Hosting✓ Green Hosted
Hosting Amazon Web Services✗CDN Vercel✓

Vercel: Hosted on AWS/Google Cloud with renewable energy commitments

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 90 KB (vs 4634 KB first visit). 372 of 373 resources are served from browser cache, saving 1.05g CO2 per repeat visit.
Info::
Repeat visit: 0.02g CO2 (first visit: 1.07g)
First visit
4634 KB
Repeat visit
90 KB

98% reduction on repeat visits

Saving 1.05g CO2 per returning visitor

372 resources served from cache · 1 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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