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https://waterstones.com

Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
70
GRADE
C
FIX
3
REVIEW
1
PASS
2
INFO
0
Device:
Mobile Desktop
Checks
6
2 PASS 1 REVIEW 3 FIX
D
CO2 Per Page Load
Action
0.81g CO2 per view
FIX
0.81g CO2 per view
Info::
0.81g CO2 per page view
This page transfers 2.9 MB, producing an estimated 0.81g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.15g, network 0.14g, end-user device 0.52g.
Got: 0.81g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 97.7 kg CO2/year
With 10,000 page views per month, this page would generate approximately 97.7 kg of CO2 annually — equivalent to charging 12217 smartphones.

0.81g

Carbon Footprint per page view

✗ Above sustainability target (0.50g)

Cleaner than 44% of websites

Sustainable Web Design model v4 · Page size: 2.9 MB

Your site
0.81g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.15g
Network
0.14g
End-user device
0.52g
At 10,000 monthly views: Monthly: 8.1 kg · Annual: 97.7 kg · ≈ 12217 smartphone charges
D
Green Hosting
Action
Unknown
FIX
Unknown
Info::
Hosting provider could not be identified
Without knowing the provider, we cannot determine their energy sourcing. Check with your hosting provider about their renewable energy commitments.
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 HostingUnable to Determine
Hosting Not identified✗CDN Not identified✗

Based on known provider commitments. Verify at thegreenwebfoundation.org

D
Carbon Budget
Action
56th percentile
FIX
56th percentile
Warning::
0.81g CO2 — above the median website (0.60g)
Heavier than an estimated 44% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 56th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.81g

56th percentile

Cleaner than 44% of websites

✗ Above the median website

vs Median 36% more
vs Target 63% more
C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A+
Repeat Visit Weight
94% cached
PASS
94% cached
Info::
94% reduction on repeat visits
Returning visitors download only 172 KB (vs 2944 KB first visit). 121 of 123 resources are served from browser cache, saving 0.77g CO2 per repeat visit.
Info::
Repeat visit: 0.05g CO2 (first visit: 0.81g)
First visit
2944 KB
Repeat visit
172 KB

94% reduction on repeat visits

Saving 0.77g CO2 per returning visitor

121 resources served from cache · 2 resources re-downloaded

A+
Transfer Efficiency
91% efficient
PASS
91% efficient
Info::
Transfer efficiency: 91%
Only 276 KB of potential savings identified. Your page is well-optimized for size.
91% efficient

Total waste: 276 KB (9% of page weight)

Unused JS 276 KB

0.08g unnecessary CO2 per visit

Actual transfer 2944 KB
Theoretical minimum 2668 KB
Potential savings 276 KB (0.08g CO2)

See Deep Analysis sections above for specific optimizations.

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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