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Sustainability

· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
85
GRADE
B
FIX
1
REVIEW
2
PASS
4
INFO
1
Checks
8
4 PASS 2 REVIEW 1 FIX
D
Transfer Efficiency
Action
54% efficient
FIX
54% efficient
Warning::
Transfer efficiency: 54%
An estimated 379 KB (46%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 379 KB of unused JavaScript. This wasted data produces 0.09g of unnecessary CO2 per page view.
54% efficient

Total waste: 379 KB (46% of page weight)

Unused JS 379 KB

0.09g unnecessary CO2 per visit

Actual transfer 829 KB
Theoretical minimum 449 KB
Potential savings 379 KB (0.09g CO2)

See Deep Analysis sections above for specific optimizations.

B
Green Hosting
Green (hosting)
REVIEW
Green (hosting)
Info::
Google Web Server uses renewable energy
Info::
Google Web Server: Verified by the Green Web Foundation
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 Google Web ServerCDN Not identified

Google Web Server: Verified by the Green Web Foundation

Based on known provider commitments. Verify at thegreenwebfoundation.org

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.
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 0.8 MB, producing an estimated 0.19g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.00g, network 0.04g, end-user device 0.15g.
Got: 0.19g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 23.0 kg CO2/year
With 10,000 page views per month, this page would generate approximately 23.0 kg of CO2 annually — equivalent to charging 2874 smartphones.
Info::
Green hosting reduces data center emissions

0.19g

Carbon Footprint per page view

Below sustainability target (0.50g)

Cleaner than 90% of websites

Sustainable Web Design model v4 · Page size: 0.8 MB

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

Energy Breakdown

Data center
0.00g
Network
0.04g
End-user device
0.15g
At 10,000 monthly views: Monthly: 1.9 kg · Annual: 23.0 kg · ≈ 2874 smartphone charges
A+
Repeat Visit Weight
93% cached
PASS
93% cached
Info::
93% reduction on repeat visits
Returning visitors download only 59 KB (vs 829 KB first visit). 41 of 42 resources are served from browser cache, saving 0.18g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.19g)
First visit
829 KB
Repeat visit
59 KB

93% reduction on repeat visits

Saving 0.18g CO2 per returning visitor

41 resources served from cache · 1 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 68% cleaner ✓
vs Target 62% cleaner ✓
A+
Green Hosting
Whether the site is served from green-energy infrastructure
PASS

Green Hosting

This site is hosted on green energy infrastructure

Provider: Google Cloud

Image Optimization
10 images, 0 KB total, 0 KB wasted
INFO

Image Optimization Audit

Total Images

10

Total Size

0 KB

10 missing dimensions 9 missing lazy loading
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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