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
0
REVIEW
4
PASS
3
INFO
0
Checks
73 PASS 4 REVIEW
BCarbon Budget31th percentileREVIEW
Carbon Budget
31th percentile
31th percentile
Info::
0.41g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 69% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 31th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
0.41g
31st percentile
Cleaner than 69% of websites
✓ Below the Web Sustainability Guidelines target
vs Median 31% cleaner ✓
vs Target 18% cleaner ✓
BTransfer Efficiency79% efficientREVIEW
Transfer Efficiency
79% efficient
79% efficient
Info::
Transfer efficiency: 79%
An estimated 367 KB (21%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 367 KB of unused JavaScript. This wasted data produces 0.08g of unnecessary CO2 per page view.
Total waste: 367 KB (21% of page weight)
Unused JS 367 KB
0.08g unnecessary CO2 per visit
Actual transfer 1782 KB
Theoretical minimum 1414 KB
Potential savings 367 KB (0.08g CO2)
See Deep Analysis sections above for specific optimizations.
BWeb Font Weight VariantsNo detectable Google Fonts weightsREVIEW
Web Font Weight Variants
No detectable Google Fonts weights
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.
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
ActionWhether the site is served from green-energy infrastructure
Green Hosting
No green hosting detected
ACO2 Per Page Load0.41g CO2 per viewPASS
CO2 Per Page Load
0.41g CO2 per view
0.41g CO2 per view
Info::
0.41g CO2 per page view
This page transfers 1.7 MB, producing an estimated 0.41g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.01g, network 0.09g, end-user device 0.32g.
Got: 0.41g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 49.4 kg CO2/year
With 10,000 page views per month, this page would generate approximately 49.4 kg of CO2 annually — equivalent to charging 6179 smartphones.
Info::
Green hosting reduces data center emissions
0.41g
Carbon Footprint per page view
✓ Below sustainability target (0.50g)
Cleaner than 69% of websites
Sustainable Web Design model v4 · Page size: 1.7 MB
Your site
0.41g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.01g
Network
0.09g
End-user device
0.32g
At 10,000 monthly views: Monthly: 4.1 kg · Annual: 49.4 kg · ≈ 6179 smartphone charges
AGreen HostingGreen (cdn)PASS
Green Hosting
Green (cdn)
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 Weight97% cachedPASS
Repeat Visit Weight
97% cached
97% cached
Info::
97% reduction on repeat visits
Returning visitors download only 50 KB (vs 1782 KB first visit). 116 of 117 resources are served from browser cache, saving 0.40g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.41g)
First visit
1782 KB
Repeat visit
50 KB
97% reduction on repeat visits
Saving 0.40g CO2 per returning visitor
116 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.