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Sustainability

· 7 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
0
Checks
7
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 identifiedCDN Not identified

Based on known provider commitments. Verify at thegreenwebfoundation.org

B
CO2 Per Page Load
0.51g CO2 per view
REVIEW
0.51g CO2 per view
Info::
0.51g CO2 per page view
This page transfers 1.8 MB, producing an estimated 0.51g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.09g, network 0.09g, end-user device 0.33g.
Got: 0.51g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 61.3 kg CO2/year
With 10,000 page views per month, this page would generate approximately 61.3 kg of CO2 annually — equivalent to charging 7667 smartphones.

0.51g

Carbon Footprint per page view

Above sustainability target (0.50g)

Cleaner than 59% of websites

Sustainable Web Design model v4 · Page size: 1.8 MB

Your site
0.51g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.09g
Network
0.09g
End-user device
0.33g
At 10,000 monthly views: Monthly: 5.1 kg · Annual: 61.3 kg · ≈ 7667 smartphone charges
B
Carbon Budget
41th percentile
REVIEW
41th percentile
Info::
0.51g CO2 — below the median website (0.60g)
Better than an estimated 59% of websites, but above the sustainability target of 0.50g. Reducing page weight would help reach the target.
Info::
Estimated 41th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.51g

41st percentile

Cleaner than 59% of websites

Above the median website

vs Median 15% cleaner ✓
vs Target 2% 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 8 KB (vs 1848 KB first visit). 154 of 155 resources are served from browser cache, saving 0.51g CO2 per repeat visit.
Info::
Repeat visit: 0.00g CO2 (first visit: 0.51g)
First visit
1848 KB
Repeat visit
8 KB

100% reduction on repeat visits

Saving 0.51g CO2 per returning visitor

154 resources served from cache · 1 resources re-downloaded

A+
Transfer Efficiency
97% efficient
PASS
97% efficient
Info::
Transfer efficiency: 97%
Only 64 KB of potential savings identified. Your page is well-optimized for size.
97% efficient

Total waste: 64 KB (3% of page weight)

Unused JS 64 KB

0.02g unnecessary CO2 per visit

Actual transfer 1848 KB
Theoretical minimum 1783 KB
Potential savings 64 KB (0.02g 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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