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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
F
CO2 Per Page Load
Action
1.93g CO2 per view
FIX
1.93g CO2 per view
Warning::
1.93g CO2 per page view
This page transfers 8.2 MB, producing an estimated 1.93g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.05g, network 0.40g, end-user device 1.49g.
Got: 1.93g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 232.1 kg CO2/year
With 10,000 page views per month, this page would generate approximately 232.1 kg of CO2 annually — equivalent to charging 29010 smartphones.
Info::
Green hosting reduces data center emissions

1.93g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 12% of websites

Sustainable Web Design model v4 · Page size: 8.2 MB

Your site
1.93g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.05g
Network
0.40g
End-user device
1.49g
At 10,000 monthly views: Monthly: 19.3 kg · Annual: 232.1 kg · ≈ 29010 smartphone charges
F
Carbon Budget
Action
88th percentile
FIX
88th percentile
Warning::
1.93g CO2 — above the median website (0.60g)
Heavier than an estimated 12% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 88th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

1.93g

88th percentile

Cleaner than 12% of websites

✗ Above the median website

vs Median 222% more
vs Target 287% more
C
Transfer Efficiency
Action
71% efficient
REVIEW
71% efficient
Warning::
Transfer efficiency: 71%
An estimated 2389 KB (29%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 2389 KB of unused JavaScript. This wasted data produces 0.55g of unnecessary CO2 per page view.
71% efficient

Total waste: 2389 KB (29% of page weight)

Unused JS 2389 KB

0.55g unnecessary CO2 per visit

Actual transfer 8367 KB
Theoretical minimum 5977 KB
Potential savings 2389 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 22 KB (vs 8367 KB first visit). 108 of 113 resources are served from browser cache, saving 1.93g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 1.93g)
First visit
8367 KB
Repeat visit
22 KB

100% reduction on repeat visits

Saving 1.93g CO2 per returning visitor

108 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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