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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
73
GRADE
C
FIX
2
REVIEW
1
PASS
3
INFO
0
Device:
Mobile Desktop
Checks
6
3 PASS 1 REVIEW 2 FIX
F
CO2 Per Page Load
Action
9.85g CO2 per view
FIX
9.85g CO2 per view
Critical::
9.85g CO2 per page view
This page transfers 41.6 MB, producing an estimated 9.85g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.25g, network 2.04g, end-user device 7.56g.
Got: 9.85g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 1181.6 kg CO2/year
With 10,000 page views per month, this page would generate approximately 1181.6 kg of CO2 annually — equivalent to charging 147704 smartphones.
Info::
Green hosting reduces data center emissions

9.85g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 5% of websites

Sustainable Web Design model v4 · Page size: 41.6 MB

Your site
9.85g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.25g
Network
2.04g
End-user device
7.56g
At 10,000 monthly views: Monthly: 98.5 kg · Annual: 1181.6 kg · ≈ 147704 smartphone charges
F
Carbon Budget
Action
95th percentile
FIX
95th percentile
Warning::
9.85g CO2 — above the median website (0.60g)
Heavier than an estimated 5% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 95th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

9.85g

95th percentile

Cleaner than 5% of websites

✗ Above the median website

vs Median 1541% more
vs Target 1869% 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 Pantheon✗CDN Fastly✓

Fastly: 100% renewable energy for edge network

Based on known provider commitments. Verify at thegreenwebfoundation.org

A+
Repeat Visit Weight
100% cached
PASS
100% cached
Info::
100% reduction on repeat visits
Returning visitors download only 41 KB (vs 42601 KB first visit). 190 of 193 resources are served from browser cache, saving 9.84g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 9.85g)
First visit
42601 KB
Repeat visit
41 KB

100% reduction on repeat visits

Saving 9.84g CO2 per returning visitor

190 resources served from cache · 3 resources re-downloaded

A+
Transfer Efficiency
98% efficient
PASS
98% efficient
Info::
Transfer efficiency: 98%
Only 761 KB of potential savings identified. Your page is well-optimized for size.
98% efficient

Total waste: 761 KB (2% of page weight)

Unused JS 761 KB

0.18g unnecessary CO2 per visit

Actual transfer 42601 KB
Theoretical minimum 41840 KB
Potential savings 761 KB (0.18g 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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