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Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
90
GRADE
A
FIX
0
REVIEW
1
PASS
5
INFO
0
Device:
Mobile Desktop
Checks
6
5 PASS 1 REVIEW
B
Transfer Efficiency
83% efficient
REVIEW
83% efficient
Info::
Transfer efficiency: 83%
An estimated 207 KB (17%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 207 KB of unused JavaScript. This wasted data produces 0.05g of unnecessary CO2 per page view.
83% efficient

Total waste: 207 KB (17% of page weight)

Unused JS 207 KB

0.05g unnecessary CO2 per visit

Actual transfer 1191 KB
Theoretical minimum 983 KB
Potential savings 207 KB (0.05g CO2)

See Deep Analysis sections above for specific optimizations.

A
CO2 Per Page Load
0.28g CO2 per view
PASS
0.28g CO2 per view
Info::
0.28g CO2 per page view
This page transfers 1.2 MB, producing an estimated 0.28g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.01g, network 0.06g, end-user device 0.21g.
Got: 0.28g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 33.0 kg CO2/year
With 10,000 page views per month, this page would generate approximately 33.0 kg of CO2 annually — equivalent to charging 4129 smartphones.
Info::
Green hosting reduces data center emissions

0.28g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 83% of websites

Sustainable Web Design model v4 · Page size: 1.2 MB

Your site
0.28g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.01g
Network
0.06g
End-user device
0.21g
At 10,000 monthly views: Monthly: 2.8 kg · Annual: 33.0 kg · ≈ 4129 smartphone charges
A+
Green Hosting
Green (both)
PASS
Green (both)
Info::
Both hosting and CDN use renewable energy
Got: Hosting: Cloudflare, CDN: Cloudflare
Info::
Cloudflare: 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 Cloudflare✓CDN Cloudflare✓

Cloudflare: 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
98% cached
PASS
98% cached
Info::
98% reduction on repeat visits
Returning visitors download only 26 KB (vs 1191 KB first visit). 58 of 60 resources are served from browser cache, saving 0.27g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.28g)
First visit
1191 KB
Repeat visit
26 KB

98% reduction on repeat visits

Saving 0.27g CO2 per returning visitor

58 resources served from cache · 2 resources re-downloaded

A
Carbon Budget
17th percentile
PASS
17th percentile
Info::
0.28g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 83% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 17th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.28g

17th percentile

Cleaner than 83% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 54% cleaner ✓
vs Target 45% cleaner ✓
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

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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