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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
80
GRADE
B
FIX
1
REVIEW
2
PASS
3
INFO
0
Checks
6
3 PASS 2 REVIEW 1 FIX
D
Carbon Budget
Action
53th percentile
FIX
53th percentile
Warning::
0.72g CO2 — above the median website (0.60g)
Heavier than an estimated 47% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 53th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.72g

53rd percentile

Cleaner than 47% of websites

Above the median website

vs Median 20% more
vs Target 44% more
B
CO2 Per Page Load
0.72g CO2 per view
REVIEW
0.72g CO2 per view
Info::
0.72g CO2 per page view
This page transfers 3.0 MB, producing an estimated 0.72g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.02g, network 0.15g, end-user device 0.55g.
Got: 0.72g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 86.4 kg CO2/year
With 10,000 page views per month, this page would generate approximately 86.4 kg of CO2 annually — equivalent to charging 10795 smartphones.
Info::
Green hosting reduces data center emissions

0.72g

Carbon Footprint per page view

Above sustainability target (0.50g)

Cleaner than 47% of websites

Sustainable Web Design model v4 · Page size: 3.0 MB

Your site
0.72g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.02g
Network
0.15g
End-user device
0.55g
At 10,000 monthly views: Monthly: 7.2 kg · Annual: 86.4 kg · ≈ 10795 smartphone charges
B
Transfer Efficiency
81% efficient
REVIEW
81% efficient
Info::
Transfer efficiency: 81%
An estimated 598 KB (19%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 598 KB of unused JavaScript. This wasted data produces 0.14g of unnecessary CO2 per page view.
81% efficient

Total waste: 598 KB (19% of page weight)

Unused JS 598 KB

0.14g unnecessary CO2 per visit

Actual transfer 3113 KB
Theoretical minimum 2515 KB
Potential savings 598 KB (0.14g CO2)

See Deep Analysis sections above for specific optimizations.

A+
Green Hosting
Green (both)
PASS
Green (both)
Info::
Both hosting and CDN use renewable energy
Got: Hosting: Amazon Web Services, CDN: Cloudflare
Info::
Amazon Web Services: Verified by the Green Web Foundation
Info::
Cloudflare: 100% renewable energy for global network since 2019
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 Amazon Web ServicesCDN Cloudflare

Amazon Web Services: Verified by the Green Web Foundation

Cloudflare: 100% renewable energy for global network since 2019

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 13 KB (vs 3113 KB first visit). 53 of 54 resources are served from browser cache, saving 0.72g CO2 per repeat visit.
Info::
Repeat visit: 0.00g CO2 (first visit: 0.72g)
First visit
3113 KB
Repeat visit
13 KB

100% reduction on repeat visits

Saving 0.72g CO2 per returning visitor

53 resources served from cache · 1 resources re-downloaded

A+
Green Hosting
Whether the site is served from green-energy infrastructure
PASS

Green Hosting

This site is hosted on green energy infrastructure

Provider: Cloudflare

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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