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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
61
GRADE
D
FIX
2
REVIEW
2
PASS
2
INFO
0
Device:
Mobile Desktop
Checks
6
2 PASS 2 REVIEW 2 FIX
D
CO2 Per Page Load
Action
1.45g CO2 per view
FIX
1.45g CO2 per view
Warning::
1.45g CO2 per page view
This page transfers 6.1 MB, producing an estimated 1.45g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.04g, network 0.30g, end-user device 1.11g.
Got: 1.45g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 173.9 kg CO2/year
With 10,000 page views per month, this page would generate approximately 173.9 kg of CO2 annually — equivalent to charging 21743 smartphones.
Info::
Green hosting reduces data center emissions

1.45g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 26% of websites

Sustainable Web Design model v4 · Page size: 6.1 MB

Your site
1.45g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.04g
Network
0.30g
End-user device
1.11g
At 10,000 monthly views: Monthly: 14.5 kg · Annual: 173.9 kg · ≈ 21743 smartphone charges
F
Carbon Budget
Action
74th percentile
FIX
74th percentile
Warning::
1.45g CO2 — above the median website (0.60g)
Heavier than an estimated 26% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 74th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

1.45g

74th percentile

Cleaner than 26% of websites

✗ Above the median website

vs Median 142% more
vs Target 190% more
C
Transfer Efficiency
Action
62% efficient
REVIEW
62% efficient
Warning::
Transfer efficiency: 62%
An estimated 2388 KB (38%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 2388 KB of unused JavaScript. This wasted data produces 0.55g of unnecessary CO2 per page view.
62% efficient

Total waste: 2388 KB (38% of page weight)

Unused JS 2388 KB

0.55g unnecessary CO2 per visit

Actual transfer 6271 KB
Theoretical minimum 3882 KB
Potential savings 2388 KB (0.55g CO2)

See Deep Analysis sections above for specific optimizations.

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 Next.js✗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 21 KB (vs 6271 KB first visit). 109 of 114 resources are served from browser cache, saving 1.44g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 1.45g)
First visit
6271 KB
Repeat visit
21 KB

100% reduction on repeat visits

Saving 1.44g CO2 per returning visitor

109 resources served from cache · 5 resources re-downloaded

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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