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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
80
GRADE
B
FIX
1
REVIEW
2
PASS
3
INFO
0
Device:
Mobile Desktop
Checks
6
3 PASS 2 REVIEW 1 FIX
D
Green Hosting
Action
Unknown
FIX
Unknown
Info::
Hosting provider could not be identified
Without knowing the provider, we cannot determine their energy sourcing. Check with your hosting provider about their 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 HostingUnable to Determine
Hosting Not identified✗CDN Not identified✗

Based on known provider commitments. Verify at thegreenwebfoundation.org

B
Transfer Efficiency
90% efficient
REVIEW
90% efficient
Info::
Transfer efficiency: 90%
An estimated 114 KB (10%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 114 KB of unused JavaScript. This wasted data produces 0.03g of unnecessary CO2 per page view.
90% efficient

Total waste: 114 KB (10% of page weight)

Unused JS 114 KB

0.03g unnecessary CO2 per visit

Actual transfer 1133 KB
Theoretical minimum 1018 KB
Potential savings 114 KB (0.03g CO2)

See Deep Analysis sections above for specific optimizations.

C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A
CO2 Per Page Load
0.31g CO2 per view
PASS
0.31g CO2 per view
Info::
0.31g CO2 per page view
This page transfers 1.1 MB, producing an estimated 0.31g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.06g, network 0.05g, end-user device 0.20g.
Got: 0.31g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 37.6 kg CO2/year
With 10,000 page views per month, this page would generate approximately 37.6 kg of CO2 annually — equivalent to charging 4703 smartphones.

0.31g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 79% of websites

Sustainable Web Design model v4 · Page size: 1.1 MB

Your site
0.31g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.06g
Network
0.05g
End-user device
0.20g
At 10,000 monthly views: Monthly: 3.1 kg · Annual: 37.6 kg · ≈ 4703 smartphone charges
A+
Repeat Visit Weight
98% cached
PASS
98% cached
Info::
98% reduction on repeat visits
Returning visitors download only 17 KB (vs 1133 KB first visit). 28 of 29 resources are served from browser cache, saving 0.31g CO2 per repeat visit.
Info::
Repeat visit: 0.00g CO2 (first visit: 0.31g)
First visit
1133 KB
Repeat visit
17 KB

98% reduction on repeat visits

Saving 0.31g CO2 per returning visitor

28 resources served from cache · 1 resources re-downloaded

A
Carbon Budget
21th percentile
PASS
21th percentile
Info::
0.31g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 79% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 21th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.31g

21st percentile

Cleaner than 79% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 48% cleaner ✓
vs Target 37% cleaner ✓
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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