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https://toronto.ca

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
68
GRADE
D
FIX
1
REVIEW
4
PASS
1
INFO
0
Device:
Mobile Desktop
Checks
6
1 PASS 4 REVIEW 1 FIX
D
Green Hosting
Action
Not green
FIX
Not green
Info::
No confirmed renewable energy commitment detected
Consider providers like Cloudflare, Google Cloud, or Vercel that match 100% of their energy use with renewables.
Info::
AWS: Renewable energy varies by region; committed to 100% by 2025
Info::
AWS CloudFront: Renewable varies by edge location
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 HostingNot Green Hosted
Hosting AWS✗CDN AWS CloudFront✗

AWS: Renewable energy varies by region; committed to 100% by 2025

AWS CloudFront: Renewable varies by edge location

Based on known provider commitments. Verify at thegreenwebfoundation.org

B
CO2 Per Page Load
0.62g CO2 per view
REVIEW
0.62g CO2 per view
Info::
0.62g CO2 per page view
This page transfers 2.2 MB, producing an estimated 0.62g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.12g, network 0.11g, end-user device 0.40g.
Got: 0.62g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 74.8 kg CO2/year
With 10,000 page views per month, this page would generate approximately 74.8 kg of CO2 annually — equivalent to charging 9351 smartphones.

0.62g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 50% of websites

Sustainable Web Design model v4 · Page size: 2.2 MB

Your site
0.62g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.12g
Network
0.11g
End-user device
0.40g
At 10,000 monthly views: Monthly: 6.2 kg · Annual: 74.8 kg · ≈ 9351 smartphone charges
B
Carbon Budget
50th percentile
REVIEW
50th percentile
Warning::
0.62g CO2 — above the median website (0.60g)
Heavier than an estimated 50% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 50th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.62g

50th percentile

Cleaner than 50% of websites

✗ Above the median website

vs Median 4% more
vs Target 25% more
C
Transfer Efficiency
Action
67% efficient
REVIEW
67% efficient
Warning::
Transfer efficiency: 67%
An estimated 742 KB (33%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 742 KB of unused JavaScript. This wasted data produces 0.21g of unnecessary CO2 per page view.
67% efficient

Total waste: 742 KB (33% of page weight)

Unused JS 742 KB

0.21g unnecessary CO2 per visit

Actual transfer 2254 KB
Theoretical minimum 1511 KB
Potential savings 742 KB (0.21g 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+
Repeat Visit Weight
97% cached
PASS
97% cached
Info::
97% reduction on repeat visits
Returning visitors download only 68 KB (vs 2254 KB first visit). 95 of 97 resources are served from browser cache, saving 0.60g CO2 per repeat visit.
Info::
Repeat visit: 0.02g CO2 (first visit: 0.62g)
First visit
2254 KB
Repeat visit
68 KB

97% reduction on repeat visits

Saving 0.60g CO2 per returning visitor

95 resources served from cache · 2 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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