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https://Vercel.app

Sustainability

· 7 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
85
GRADE
B
FIX
3
REVIEW
2
PASS
2
INFO
0
Device:
Mobile Desktop
Checks
7
2 PASS 2 REVIEW 3 FIX
D
CO2 Per Page Load
Action
1.10g CO2 per view
FIX
1.10g CO2 per view
Warning::
1.10g CO2 per page view
This page transfers 4.7 MB, producing an estimated 1.10g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.03g, network 0.23g, end-user device 0.85g.
Got: 1.10g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 132.5 kg CO2/year
With 10,000 page views per month, this page would generate approximately 132.5 kg of CO2 annually — equivalent to charging 16561 smartphones.
Info::
Green hosting reduces data center emissions

1.10g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 36% of websites

Sustainable Web Design model v4 · Page size: 4.7 MB

Your site
1.10g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.03g
Network
0.23g
End-user device
0.85g
At 10,000 monthly views: Monthly: 11.0 kg · Annual: 132.5 kg · ≈ 16561 smartphone charges
D
Carbon Budget
Action
64th percentile
FIX
64th percentile
Warning::
1.10g CO2 — above the median website (0.60g)
Heavier than an estimated 36% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 64th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

1.10g

64th percentile

Cleaner than 36% of websites

✗ Above the median website

vs Median 84% more
vs Target 121% more
D
Transfer Efficiency
Action
55% efficient
FIX
55% efficient
Warning::
Transfer efficiency: 55%
An estimated 2169 KB (45%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 2169 KB of unused JavaScript. This wasted data produces 0.50g of unnecessary CO2 per page view.
55% efficient

Total waste: 2169 KB (45% of page weight)

Unused JS 2169 KB

0.50g unnecessary CO2 per visit

Actual transfer 4776 KB
Theoretical minimum 2607 KB
Potential savings 2169 KB (0.50g CO2)

See Deep Analysis sections above for specific optimizations.

B
Web Font Weight Variants
No detectable Google Fonts weights
REVIEW
No detectable Google Fonts weights
Info::
No detectable Google Fonts weights
The analyzer detects font weights via Google Fonts URL parameters (~70% of font-using sites). Self-hosted fonts and non-Google CDN fonts aren't visible to URL-based detection. If you self-host fonts, manually audit how many @font-face weights you ship -- 2-3 weights per family is typically enough; 5+ is usually unused payload.
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 Next.js✗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
99% cached
PASS
99% cached
Info::
99% reduction on repeat visits
Returning visitors download only 50 KB (vs 4776 KB first visit). 233 of 234 resources are served from browser cache, saving 1.09g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 1.10g)
First visit
4776 KB
Repeat visit
50 KB

99% reduction on repeat visits

Saving 1.09g CO2 per returning visitor

233 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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