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https://manuelferrara.com

Sustainability

· 8 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
4
PASS
2
INFO
1
Device:
Mobile Desktop
Checks
8
2 PASS 4 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
CO2 Per Page Load
0.57g CO2 per view
REVIEW
0.57g CO2 per view
Info::
0.57g CO2 per page view
This page transfers 2.0 MB, producing an estimated 0.57g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.11g, network 0.10g, end-user device 0.37g.
Got: 0.57g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 68.5 kg CO2/year
With 10,000 page views per month, this page would generate approximately 68.5 kg of CO2 annually — equivalent to charging 8564 smartphones.

0.57g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 53% of websites

Sustainable Web Design model v4 · Page size: 2.0 MB

Your site
0.57g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.11g
Network
0.10g
End-user device
0.37g
At 10,000 monthly views: Monthly: 5.7 kg · Annual: 68.5 kg · ≈ 8564 smartphone charges
B
Carbon Budget
47th percentile
REVIEW
47th percentile
Info::
0.57g CO2 — below the median website (0.60g)
Better than an estimated 53% of websites, but above the sustainability target of 0.50g. Reducing page weight would help reach the target.
Info::
Estimated 47th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.57g

47th percentile

Cleaner than 53% of websites

✗ Above the median website

vs Median 5% cleaner ✓
vs Target 14% more
B
Web Font Weight Variants
No detectable Google Fonts weights
REVIEW
No detectable Google Fonts weights
Info::
No detectable Google Fonts weights
The analyzer detects font weights via Google Fonts URL parameters (~70% of font-using sites). Self-hosted fonts and non-Google CDN fonts aren't visible to URL-based detection. If you self-host fonts, manually audit how many @font-face weights you ship -- 2-3 weights per family is typically enough; 5+ is usually unused payload.
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A+
Repeat Visit Weight
100% cached
PASS
100% cached
Info::
100% reduction on repeat visits
Returning visitors download only 2 KB (vs 2064 KB first visit). 4 of 5 resources are served from browser cache, saving 0.57g CO2 per repeat visit.
Info::
Repeat visit: 0.00g CO2 (first visit: 0.57g)
First visit
2064 KB
Repeat visit
2 KB

100% reduction on repeat visits

Saving 0.57g CO2 per returning visitor

4 resources served from cache · 1 resources re-downloaded

A+
Transfer Efficiency
100% efficient
PASS
100% efficient
Info::
Transfer efficiency: 100%
Only 0 KB of potential savings identified. Your page is well-optimized for size.
100% efficient
Actual transfer 2064 KB
Theoretical minimum 2064 KB

See Deep Analysis sections above for specific optimizations.

Image Optimization
1 images, 2055 KB total, 1855 KB wasted
INFO

Image Optimization Audit

Total Images

1

Total Size

2055 KB

Oversized

1

Wasted

1855 KB

1 missing dimensions
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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