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https://mimecast.com

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
53
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
2.43g CO2 per view
FIX
2.43g CO2 per view
Critical::
2.43g CO2 per page view
This page transfers 8.6 MB, producing an estimated 2.43g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.45g, network 0.42g, end-user device 1.56g.
Got: 2.43g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 292.1 kg CO2/year
With 10,000 page views per month, this page would generate approximately 292.1 kg of CO2 annually — equivalent to charging 36515 smartphones.

2.43g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 5% of websites

Sustainable Web Design model v4 · Page size: 8.6 MB

Your site
2.43g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.45g
Network
0.42g
End-user device
1.56g
At 10,000 monthly views: Monthly: 24.3 kg · Annual: 292.1 kg · ≈ 36515 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::
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 Amazon Web Services✗CDN Varnish✗

Based on known provider commitments. Verify at thegreenwebfoundation.org

F
Carbon Budget
Action
95th percentile
FIX
95th percentile
Warning::
2.43g 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

2.43g

95th percentile

Cleaner than 5% of websites

✗ Above the median website

vs Median 306% more
vs Target 387% more
B
Transfer Efficiency
87% efficient
REVIEW
87% efficient
Info::
Transfer efficiency: 87%
An estimated 1164 KB (13%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 1164 KB of unused JavaScript. This wasted data produces 0.32g of unnecessary CO2 per page view.
87% efficient

Total waste: 1164 KB (13% of page weight)

Unused JS 1164 KB

0.32g unnecessary CO2 per visit

Actual transfer 8802 KB
Theoretical minimum 7637 KB
Potential savings 1164 KB (0.32g 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
100% cached
PASS
100% cached
Info::
100% reduction on repeat visits
Returning visitors download only 28 KB (vs 8802 KB first visit). 220 of 222 resources are served from browser cache, saving 2.43g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 2.43g)
First visit
8802 KB
Repeat visit
28 KB

100% reduction on repeat visits

Saving 2.43g CO2 per returning visitor

220 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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