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https://penguin.co.uk

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
81
GRADE
B
FIX
0
REVIEW
4
PASS
2
INFO
0
Device:
Mobile Desktop
Checks
6
2 PASS 4 REVIEW
B
CO2 Per Page Load
0.50g CO2 per view
REVIEW
0.50g CO2 per view
Info::
0.50g CO2 per page view
This page transfers 2.1 MB, producing an estimated 0.50g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.01g, network 0.10g, end-user device 0.39g.
Got: 0.50g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 60.3 kg CO2/year
With 10,000 page views per month, this page would generate approximately 60.3 kg of CO2 annually — equivalent to charging 7534 smartphones.
Info::
Green hosting reduces data center emissions

0.50g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 60% of websites

Sustainable Web Design model v4 · Page size: 2.1 MB

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

Energy Breakdown

Data center
0.01g
Network
0.10g
End-user device
0.39g
At 10,000 monthly views: Monthly: 5.0 kg · Annual: 60.3 kg · ≈ 7534 smartphone charges
B
Carbon Budget
40th percentile
REVIEW
40th percentile
Info::
0.50g CO2 — below the median website (0.60g)
Better than an estimated 60% of websites, but above the sustainability target of 0.50g. Reducing page weight would help reach the target.
Info::
Estimated 40th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.50g

40th percentile

Cleaner than 60% of websites

✗ Above the median website

vs Median 16% cleaner ✓
vs Target 0% more
B
Transfer Efficiency
89% efficient
REVIEW
89% efficient
Info::
Transfer efficiency: 89%
An estimated 237 KB (11%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 237 KB of unused JavaScript. This wasted data produces 0.05g of unnecessary CO2 per page view.
89% efficient

Total waste: 237 KB (11% of page weight)

Unused JS 237 KB

0.05g unnecessary CO2 per visit

Actual transfer 2173 KB
Theoretical minimum 1935 KB
Potential savings 237 KB (0.05g 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
Green Hosting
Green (cdn)
PASS
Green (cdn)
Info::
Cloudflare CDN uses renewable energy
Since most traffic is served through the CDN, the majority of data transfer energy is renewable.
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 Next.js✗CDN Cloudflare✓

Cloudflare: 100% renewable energy for global network since 2019

Based on known provider commitments. Verify at thegreenwebfoundation.org

A+
Repeat Visit Weight
97% cached
PASS
97% cached
Info::
97% reduction on repeat visits
Returning visitors download only 68 KB (vs 2173 KB first visit). 98 of 99 resources are served from browser cache, saving 0.49g CO2 per repeat visit.
Info::
Repeat visit: 0.02g CO2 (first visit: 0.50g)
First visit
2173 KB
Repeat visit
68 KB

97% reduction on repeat visits

Saving 0.49g CO2 per returning visitor

98 resources served from cache · 1 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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