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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
82
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

C
Transfer Efficiency
Action
61% efficient
REVIEW
61% efficient
Warning::
Transfer efficiency: 61%
An estimated 262 KB (39%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 262 KB of unused JavaScript. This wasted data produces 0.07g of unnecessary CO2 per page view.
61% efficient

Total waste: 262 KB (39% of page weight)

Unused JS 262 KB

0.07g unnecessary CO2 per visit

Actual transfer 672 KB
Theoretical minimum 409 KB
Potential savings 262 KB (0.07g 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
0.19g CO2 per view
PASS
0.19g CO2 per view
Info::
0.19g CO2 per page view
This page transfers 0.7 MB, producing an estimated 0.19g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.03g, network 0.03g, end-user device 0.12g.
Got: 0.19g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 22.3 kg CO2/year
With 10,000 page views per month, this page would generate approximately 22.3 kg of CO2 annually — equivalent to charging 2790 smartphones.

0.19g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 90% of websites

Sustainable Web Design model v4 · Page size: 0.7 MB

Your site
0.19g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.03g
Network
0.03g
End-user device
0.12g
At 10,000 monthly views: Monthly: 1.9 kg · Annual: 22.3 kg · ≈ 2790 smartphone charges
A+
Repeat Visit Weight
98% cached
PASS
98% cached
Info::
98% reduction on repeat visits
Returning visitors download only 13 KB (vs 672 KB first visit). 29 of 32 resources are served from browser cache, saving 0.18g CO2 per repeat visit.
Info::
Repeat visit: 0.00g CO2 (first visit: 0.19g)
First visit
672 KB
Repeat visit
13 KB

98% reduction on repeat visits

Saving 0.18g CO2 per returning visitor

29 resources served from cache · 3 resources re-downloaded

A+
Carbon Budget
10th percentile
PASS
10th percentile
Info::
0.19g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 90% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 10th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.19g

10th percentile

Cleaner than 90% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 69% cleaner ✓
vs Target 63% 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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