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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
86
GRADE
B
FIX
0
REVIEW
1
PASS
5
INFO
0
Device:
Mobile Desktop
Checks
6
5 PASS 1 REVIEW
C
Transfer Efficiency
Action
71% efficient
REVIEW
71% efficient
Warning::
Transfer efficiency: 71%
An estimated 501 KB (29%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 501 KB of unused JavaScript. This wasted data produces 0.12g of unnecessary CO2 per page view.
71% efficient

Total waste: 501 KB (29% of page weight)

Unused JS 501 KB

0.12g unnecessary CO2 per visit

Actual transfer 1719 KB
Theoretical minimum 1217 KB
Potential savings 501 KB (0.12g CO2)

See Deep Analysis sections above for specific optimizations.

A
CO2 Per Page Load
0.40g CO2 per view
PASS
0.40g CO2 per view
Info::
0.40g CO2 per page view
This page transfers 1.7 MB, producing an estimated 0.40g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.01g, network 0.08g, end-user device 0.31g.
Got: 0.40g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 47.7 kg CO2/year
With 10,000 page views per month, this page would generate approximately 47.7 kg of CO2 annually — equivalent to charging 5960 smartphones.
Info::
Green hosting reduces data center emissions

0.40g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 71% of websites

Sustainable Web Design model v4 · Page size: 1.7 MB

Your site
0.40g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.01g
Network
0.08g
End-user device
0.31g
At 10,000 monthly views: Monthly: 4.0 kg · Annual: 47.7 kg · ≈ 5960 smartphone charges
A+
Green Hosting
Green (both)
PASS
Green (both)
Info::
Both hosting and CDN use renewable energy
Got: Hosting: Amazon Web Services, CDN: Cloudflare
Info::
Amazon Web Services: 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 Amazon Web Services✓CDN Cloudflare✓

Amazon Web Services: 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
96% cached
PASS
96% cached
Info::
96% reduction on repeat visits
Returning visitors download only 65 KB (vs 1719 KB first visit). 69 of 70 resources are served from browser cache, saving 0.38g CO2 per repeat visit.
Info::
Repeat visit: 0.02g CO2 (first visit: 0.40g)
First visit
1719 KB
Repeat visit
65 KB

96% reduction on repeat visits

Saving 0.38g CO2 per returning visitor

69 resources served from cache · 1 resources re-downloaded

A
Carbon Budget
29th percentile
PASS
29th percentile
Info::
0.40g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 71% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 29th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.40g

29th percentile

Cleaner than 71% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 34% cleaner ✓
vs Target 21% 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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