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https://nice.org.uk

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
78
GRADE
C
FIX
1
REVIEW
2
PASS
3
INFO
0
Device:
Mobile Desktop
Checks
6
3 PASS 2 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::
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 Not identified✗

Based on known provider commitments. Verify at thegreenwebfoundation.org

B
Transfer Efficiency
78% efficient
REVIEW
78% efficient
Info::
Transfer efficiency: 78%
An estimated 254 KB (22%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 254 KB of unused JavaScript. This wasted data produces 0.07g of unnecessary CO2 per page view.
78% efficient

Total waste: 254 KB (22% of page weight)

Unused JS 254 KB

0.07g unnecessary CO2 per visit

Actual transfer 1177 KB
Theoretical minimum 923 KB
Potential savings 254 KB (0.07g 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
CO2 Per Page Load
0.33g CO2 per view
PASS
0.33g CO2 per view
Info::
0.33g CO2 per page view
This page transfers 1.1 MB, producing an estimated 0.33g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.06g, network 0.06g, end-user device 0.21g.
Got: 0.33g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 39.1 kg CO2/year
With 10,000 page views per month, this page would generate approximately 39.1 kg of CO2 annually — equivalent to charging 4884 smartphones.

0.33g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 78% of websites

Sustainable Web Design model v4 · Page size: 1.1 MB

Your site
0.33g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.06g
Network
0.06g
End-user device
0.21g
At 10,000 monthly views: Monthly: 3.3 kg · Annual: 39.1 kg · ≈ 4884 smartphone charges
A+
Repeat Visit Weight
97% cached
PASS
97% cached
Info::
97% reduction on repeat visits
Returning visitors download only 37 KB (vs 1177 KB first visit). 32 of 34 resources are served from browser cache, saving 0.32g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.33g)
First visit
1177 KB
Repeat visit
37 KB

97% reduction on repeat visits

Saving 0.32g CO2 per returning visitor

32 resources served from cache · 2 resources re-downloaded

A
Carbon Budget
22th percentile
PASS
22th percentile
Info::
0.33g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 78% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 22th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.33g

22nd percentile

Cleaner than 78% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 46% cleaner ✓
vs Target 35% cleaner ✓
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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