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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
64% efficient
REVIEW
64% efficient
Warning::
Transfer efficiency: 64%
An estimated 577 KB (36%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 577 KB of unused JavaScript. This wasted data produces 0.13g of unnecessary CO2 per page view.
64% efficient

Total waste: 577 KB (36% of page weight)

Unused JS 577 KB

0.13g unnecessary CO2 per visit

Actual transfer 1599 KB
Theoretical minimum 1021 KB
Potential savings 577 KB (0.13g CO2)

See Deep Analysis sections above for specific optimizations.

A
CO2 Per Page Load
0.37g CO2 per view
PASS
0.37g CO2 per view
Info::
0.37g CO2 per page view
This page transfers 1.6 MB, producing an estimated 0.37g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.01g, network 0.08g, end-user device 0.28g.
Got: 0.37g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 44.4 kg CO2/year
With 10,000 page views per month, this page would generate approximately 44.4 kg of CO2 annually — equivalent to charging 5544 smartphones.
Info::
Green hosting reduces data center emissions

0.37g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 74% of websites

Sustainable Web Design model v4 · Page size: 1.6 MB

Your site
0.37g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.01g
Network
0.08g
End-user device
0.28g
At 10,000 monthly views: Monthly: 3.7 kg · Annual: 44.4 kg · ≈ 5544 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
83% cached
PASS
83% cached
Info::
83% reduction on repeat visits
Returning visitors download only 268 KB (vs 1599 KB first visit). 97 of 98 resources are served from browser cache, saving 0.31g CO2 per repeat visit.
Info::
Repeat visit: 0.06g CO2 (first visit: 0.37g)
First visit
1599 KB
Repeat visit
268 KB

83% reduction on repeat visits

Saving 0.31g CO2 per returning visitor

97 resources served from cache · 1 resources re-downloaded

A
Carbon Budget
26th percentile
PASS
26th percentile
Info::
0.37g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 74% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 26th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.37g

26th percentile

Cleaner than 74% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 38% cleaner ✓
vs Target 26% 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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