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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
81
GRADE
B
FIX
2
REVIEW
1
PASS
4
INFO
1
Checks
8
4 PASS 1 REVIEW 2 FIX
D
CO2 Per Page Load
Action
0.91g CO2 per view
FIX
0.91g CO2 per view
Info::
0.91g CO2 per page view
This page transfers 3.9 MB, producing an estimated 0.91g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.02g, network 0.19g, end-user device 0.70g.
Got: 0.91g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 109.7 kg CO2/year
With 10,000 page views per month, this page would generate approximately 109.7 kg of CO2 annually — equivalent to charging 13706 smartphones.
Info::
Green hosting reduces data center emissions

0.91g

Carbon Footprint per page view

Above sustainability target (0.50g)

Cleaner than 42% of websites

Sustainable Web Design model v4 · Page size: 3.9 MB

Your site
0.91g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.02g
Network
0.19g
End-user device
0.70g
At 10,000 monthly views: Monthly: 9.1 kg · Annual: 109.7 kg · ≈ 13706 smartphone charges
D
Carbon Budget
Action
58th percentile
FIX
58th percentile
Warning::
0.91g CO2 — above the median website (0.60g)
Heavier than an estimated 42% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 58th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.91g

58th percentile

Cleaner than 42% of websites

Above the median website

vs Median 52% more
vs Target 83% 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.
A+
Green Hosting
Green (both)
PASS
Green (both)
Info::
Both hosting and CDN use renewable energy
Got: Hosting: Cloudflare, CDN: Cloudflare
Info::
Cloudflare: Verified by the Green Web Foundation
Info::
Cloudflare: 100% renewable energy for global network since 2019
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 CloudflareCDN Cloudflare

Cloudflare: Verified by the Green Web Foundation

Cloudflare: 100% renewable energy for global network since 2019

Based on known provider commitments. Verify at thegreenwebfoundation.org

A+
Repeat Visit Weight
96% cached
PASS
96% cached
Info::
96% reduction on repeat visits
Returning visitors download only 144 KB (vs 3953 KB first visit). 155 of 157 resources are served from browser cache, saving 0.88g CO2 per repeat visit.
Info::
Repeat visit: 0.03g CO2 (first visit: 0.91g)
First visit
3953 KB
Repeat visit
144 KB

96% reduction on repeat visits

Saving 0.88g CO2 per returning visitor

155 resources served from cache · 2 resources re-downloaded

A+
Transfer Efficiency
95% efficient
PASS
95% efficient
Info::
Transfer efficiency: 95%
Only 193 KB of potential savings identified. Your page is well-optimized for size.
95% efficient

Total waste: 193 KB (5% of page weight)

Unused JS 193 KB

0.04g unnecessary CO2 per visit

Actual transfer 3953 KB
Theoretical minimum 3759 KB
Potential savings 193 KB (0.04g CO2)

See Deep Analysis sections above for specific optimizations.

A+
Green Hosting
Whether the site is served from green-energy infrastructure
PASS

Green Hosting

This site is hosted on green energy infrastructure

Provider: Cloudflare

Image Optimization
76 images, 16 KB total, 13 KB wasted
INFO

Image Optimization Audit

Total Images

76

Total Size

16 KB

Oversized

14

Wasted

13 KB

76 missing dimensions 74 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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