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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
85
GRADE
B
FIX
0
REVIEW
3
PASS
3
INFO
0
Device:
Mobile Desktop
Checks
6
3 PASS 3 REVIEW
B
CO2 Per Page Load
0.59g CO2 per view
REVIEW
0.59g CO2 per view
Info::
0.59g CO2 per page view
This page transfers 2.5 MB, producing an estimated 0.59g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.01g, network 0.12g, end-user device 0.45g.
Got: 0.59g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 70.7 kg CO2/year
With 10,000 page views per month, this page would generate approximately 70.7 kg of CO2 annually — equivalent to charging 8835 smartphones.
Info::
Green hosting reduces data center emissions

0.59g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 52% of websites

Sustainable Web Design model v4 · Page size: 2.5 MB

Your site
0.59g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.01g
Network
0.12g
End-user device
0.45g
At 10,000 monthly views: Monthly: 5.9 kg · Annual: 70.7 kg · ≈ 8835 smartphone charges
B
Carbon Budget
48th percentile
REVIEW
48th percentile
Info::
0.59g CO2 — below the median website (0.60g)
Better than an estimated 52% of websites, but above the sustainability target of 0.50g. Reducing page weight would help reach the target.
Info::
Estimated 48th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.59g

48th percentile

Cleaner than 52% of websites

✗ Above the median website

vs Median 2% cleaner ✓
vs Target 18% more
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A
Green Hosting
Green (cdn)
PASS
Green (cdn)
Info::
Fastly CDN uses renewable energy
Since most traffic is served through the CDN, the majority of data transfer energy is renewable.
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 Not identified✗CDN Fastly✓

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 71 KB (vs 2548 KB first visit). 175 of 178 resources are served from browser cache, saving 0.57g CO2 per repeat visit.
Info::
Repeat visit: 0.02g CO2 (first visit: 0.59g)
First visit
2548 KB
Repeat visit
71 KB

97% reduction on repeat visits

Saving 0.57g CO2 per returning visitor

175 resources served from cache · 3 resources re-downloaded

A+
Transfer Efficiency
95% efficient
PASS
95% efficient
Info::
Transfer efficiency: 95%
Only 137 KB of potential savings identified. Your page is well-optimized for size.
95% efficient

Total waste: 137 KB (5% of page weight)

Unused JS 137 KB

0.03g unnecessary CO2 per visit

Actual transfer 2548 KB
Theoretical minimum 2411 KB
Potential savings 137 KB (0.03g 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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