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https://Dylankotzer.com

Sustainability

· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
95
GRADE
A
FIX
0
REVIEW
1
PASS
6
INFO
1
Device:
Mobile Desktop
Checks
8
6 PASS 1 REVIEW
B
Transfer Efficiency
80% efficient
REVIEW
80% efficient
Info::
Transfer efficiency: 80%
An estimated 195 KB (20%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 195 KB of unused JavaScript. This wasted data produces 0.05g of unnecessary CO2 per page view.
80% efficient

Total waste: 195 KB (20% of page weight)

Unused JS 195 KB

0.05g unnecessary CO2 per visit

Actual transfer 959 KB
Theoretical minimum 764 KB
Potential savings 195 KB (0.05g CO2)

See Deep Analysis sections above for specific optimizations.

A
CO2 Per Page Load
0.22g CO2 per view
PASS
0.22g CO2 per view
Info::
0.22g CO2 per page view
This page transfers 0.9 MB, producing an estimated 0.22g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.01g, network 0.05g, end-user device 0.17g.
Got: 0.22g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 26.6 kg CO2/year
With 10,000 page views per month, this page would generate approximately 26.6 kg of CO2 annually — equivalent to charging 3326 smartphones.
Info::
Green hosting reduces data center emissions

0.22g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 88% of websites

Sustainable Web Design model v4 · Page size: 0.9 MB

Your site
0.22g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.01g
Network
0.05g
End-user device
0.17g
At 10,000 monthly views: Monthly: 2.2 kg · Annual: 26.6 kg · ≈ 3326 smartphone charges
A+
Green Hosting
Green (both)
PASS
Green (both)
Info::
Both hosting and CDN use renewable energy
Got: Hosting: Vercel, CDN: Cloudflare
Info::
Vercel: Verified by the Green Web Foundation
Info::
Cloudflare: 100% renewable energy for global network since 2019
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 Vercel✓CDN Cloudflare✓

Vercel: Verified by the Green Web Foundation

Cloudflare: 100% renewable energy for global network since 2019

Based on known provider commitments. Verify at thegreenwebfoundation.org

A+
Repeat Visit Weight
100% cached
PASS
100% cached
Info::
100% reduction on repeat visits
Returning visitors download only 1 KB (vs 959 KB first visit). 12 of 13 resources are served from browser cache, saving 0.22g CO2 per repeat visit.
Info::
Repeat visit: 0.00g CO2 (first visit: 0.22g)
First visit
959 KB
Repeat visit
1 KB

100% reduction on repeat visits

Saving 0.22g CO2 per returning visitor

12 resources served from cache · 1 resources re-downloaded

A
Carbon Budget
12th percentile
PASS
12th percentile
Info::
0.22g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 88% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 12th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.22g

12th percentile

Cleaner than 88% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 63% cleaner ✓
vs Target 56% cleaner ✓
A+
Web Font Weight Variants
4 font weights loaded across 1 famil(y/ies) -- reasonable
PASS
4 font weights loaded across 1 famil(y/ies) -- reasonable
Info::
4 font weight(s) loaded across 1 famil(y/ies)
A+
Green Hosting
Whether the site is served from green-energy infrastructure
PASS

Green Hosting

This site is hosted on green energy infrastructure

Provider: Cloudflare

Image Optimization
1 images, 269 KB total, 265 KB wasted
INFO

Image Optimization Audit

Total Images

1

Total Size

269 KB

Oversized

1

Wasted

265 KB

1 missing dimensions 1 missing lazy loading
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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