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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
100
GRADE
A+
FIX
0
REVIEW
1
PASS
5
INFO
0
Device:
Mobile Desktop
Checks
6
5 PASS 1 REVIEW
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
0.06g CO2 per view
PASS
0.06g CO2 per view
Info::
0.06g CO2 per page view
This page transfers 0.2 MB, producing an estimated 0.06g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.00g, network 0.01g, end-user device 0.04g.
Got: 0.06g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 6.9 kg CO2/year
With 10,000 page views per month, this page would generate approximately 6.9 kg of CO2 annually — equivalent to charging 862 smartphones.
Info::
Green hosting reduces data center emissions

0.06g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 90% of websites

Sustainable Web Design model v4 · Page size: 0.2 MB

Your site
0.06g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.00g
Network
0.01g
End-user device
0.04g
At 10,000 monthly views: Monthly: 0.6 kg · Annual: 6.9 kg · ≈ 862 smartphone charges
A+
Green Hosting
Green (both)
PASS
Green (both)
Info::
Both hosting and CDN use renewable energy
Got: Hosting: GitHub Pages, CDN: Fastly
Info::
GitHub Pages: Hosted on Azure/GitHub with Microsoft carbon-negative commitment
Info::
Fastly: 100% renewable energy for edge network
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 GitHub Pages✓CDN Fastly✓

GitHub Pages: Hosted on Azure/GitHub with Microsoft carbon-negative commitment

Fastly: 100% renewable energy for edge network

Based on known provider commitments. Verify at thegreenwebfoundation.org

A+
Repeat Visit Weight
97% cached
PASS
97% cached
Info::
97% reduction on repeat visits
Returning visitors download only 6 KB (vs 248 KB first visit). 20 of 21 resources are served from browser cache, saving 0.06g CO2 per repeat visit.
Info::
Repeat visit: 0.00g CO2 (first visit: 0.06g)
First visit
248 KB
Repeat visit
6 KB

97% reduction on repeat visits

Saving 0.06g CO2 per returning visitor

20 resources served from cache · 1 resources re-downloaded

A+
Carbon Budget
10th percentile
PASS
10th percentile
Info::
0.06g 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

0.06g

10th percentile

Cleaner than 90% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 90% cleaner ✓
vs Target 89% cleaner ✓
A+
Transfer Efficiency
92% efficient
PASS
92% efficient
Info::
Transfer efficiency: 92%
Only 20 KB of potential savings identified. Your page is well-optimized for size.
92% efficient

Total waste: 20 KB (8% of page weight)

Unused JS 20 KB

0.00g unnecessary CO2 per visit

Actual transfer 248 KB
Theoretical minimum 228 KB
Potential savings 20 KB (0.00g CO2)

See Deep Analysis sections above for specific optimizations.

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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