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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
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
89% efficient
REVIEW
89% efficient
Info::
Transfer efficiency: 89%
An estimated 124 KB (11%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 124 KB of unused JavaScript. This wasted data produces 0.03g of unnecessary CO2 per page view.
89% efficient

Total waste: 124 KB (11% of page weight)

Unused JS 124 KB

0.03g unnecessary CO2 per visit

Actual transfer 1110 KB
Theoretical minimum 985 KB
Potential savings 124 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: 36.9 kg CO2/year
With 10,000 page views per month, this page would generate approximately 36.9 kg of CO2 annually — equivalent to charging 4606 smartphones.

0.31g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 80% 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: 36.9 kg · ≈ 4606 smartphone charges
A+
Repeat Visit Weight
96% cached
PASS
96% cached
Info::
96% reduction on repeat visits
Returning visitors download only 42 KB (vs 1110 KB first visit). 67 of 70 resources are served from browser cache, saving 0.30g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.31g)
First visit
1110 KB
Repeat visit
42 KB

96% reduction on repeat visits

Saving 0.30g CO2 per returning visitor

67 resources served from cache · 3 resources re-downloaded

A
Carbon Budget
20th percentile
PASS
20th percentile
Info::
0.31g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 80% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 20th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.31g

20th percentile

Cleaner than 80% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 49% cleaner ✓
vs Target 39% 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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