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https://outsideonline.com

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
2
PASS
2
INFO
0
Device:
Mobile Desktop
Checks
6
2 PASS 2 REVIEW 2 FIX
D
CO2 Per Page Load
Action
1.33g CO2 per view
FIX
1.33g CO2 per view
Warning::
1.33g CO2 per page view
This page transfers 5.6 MB, producing an estimated 1.33g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.03g, network 0.27g, end-user device 1.02g.
Got: 1.33g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 159.0 kg CO2/year
With 10,000 page views per month, this page would generate approximately 159.0 kg of CO2 annually — equivalent to charging 19877 smartphones.
Info::
Green hosting reduces data center emissions

1.33g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 30% of websites

Sustainable Web Design model v4 · Page size: 5.6 MB

Your site
1.33g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.03g
Network
0.27g
End-user device
1.02g
At 10,000 monthly views: Monthly: 13.3 kg · Annual: 159.0 kg · ≈ 19877 smartphone charges
D
Carbon Budget
Action
70th percentile
FIX
70th percentile
Warning::
1.33g CO2 — above the median website (0.60g)
Heavier than an estimated 30% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 70th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

1.33g

70th percentile

Cleaner than 30% of websites

✗ Above the median website

vs Median 121% more
vs Target 165% more
B
Transfer Efficiency
87% efficient
REVIEW
87% efficient
Info::
Transfer efficiency: 87%
An estimated 761 KB (13%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 761 KB of unused JavaScript. This wasted data produces 0.18g of unnecessary CO2 per page view.
87% efficient

Total waste: 761 KB (13% of page weight)

Unused JS 761 KB

0.18g unnecessary CO2 per visit

Actual transfer 5733 KB
Theoretical minimum 4971 KB
Potential savings 761 KB (0.18g 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::
Vercel CDN uses renewable energy
Since most traffic is served through the CDN, the majority of data transfer energy is renewable.
Info::
Vercel: Hosted on AWS/Google Cloud with renewable energy commitments
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 Snowplow Analytics✗CDN Vercel✓

Vercel: Hosted on AWS/Google Cloud with renewable energy commitments

Based on known provider commitments. Verify at thegreenwebfoundation.org

A+
Repeat Visit Weight
99% cached
PASS
99% cached
Info::
99% reduction on repeat visits
Returning visitors download only 60 KB (vs 5733 KB first visit). 323 of 332 resources are served from browser cache, saving 1.31g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 1.33g)
First visit
5733 KB
Repeat visit
60 KB

99% reduction on repeat visits

Saving 1.31g CO2 per returning visitor

323 resources served from cache · 9 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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