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https://westjet.com

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
49
GRADE
F
FIX
3
REVIEW
2
PASS
1
INFO
0
Device:
Mobile Desktop
Checks
6
1 PASS 2 REVIEW 3 FIX
F
CO2 Per Page Load
Action
2.23g CO2 per view
FIX
2.23g CO2 per view
Critical::
2.23g CO2 per page view
This page transfers 7.9 MB, producing an estimated 2.23g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.41g, network 0.38g, end-user device 1.43g.
Got: 2.23g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 267.2 kg CO2/year
With 10,000 page views per month, this page would generate approximately 267.2 kg of CO2 annually — equivalent to charging 33405 smartphones.

2.23g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 5% of websites

Sustainable Web Design model v4 · Page size: 7.9 MB

Your site
2.23g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.41g
Network
0.38g
End-user device
1.43g
At 10,000 monthly views: Monthly: 22.3 kg · Annual: 267.2 kg · ≈ 33405 smartphone charges
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::
Akamai: Committed to 50% renewable by 2030
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 Not identified✗CDN Akamai✗

Akamai: Committed to 50% renewable by 2030

Based on known provider commitments. Verify at thegreenwebfoundation.org

F
Carbon Budget
Action
95th percentile
FIX
95th percentile
Warning::
2.23g CO2 — above the median website (0.60g)
Heavier than an estimated 5% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 95th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

2.23g

95th percentile

Cleaner than 5% of websites

✗ Above the median website

vs Median 271% more
vs Target 345% more
C
Transfer Efficiency
Action
70% efficient
REVIEW
70% efficient
Warning::
Transfer efficiency: 70%
An estimated 2391 KB (30%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 2391 KB of unused JavaScript. This wasted data produces 0.66g of unnecessary CO2 per page view.
70% efficient

Total waste: 2391 KB (30% of page weight)

Unused JS 2391 KB

0.66g unnecessary CO2 per visit

Actual transfer 8052 KB
Theoretical minimum 5661 KB
Potential savings 2391 KB (0.66g 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
99% cached
PASS
99% cached
Info::
99% reduction on repeat visits
Returning visitors download only 52 KB (vs 8052 KB first visit). 178 of 183 resources are served from browser cache, saving 2.21g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 2.23g)
First visit
8052 KB
Repeat visit
52 KB

99% reduction on repeat visits

Saving 2.21g CO2 per returning visitor

178 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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