https://once-upon-a-book-club.myshopify.com
Sustainability
· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
68
GRADE
D
FIX
2
REVIEW
3
PASS
2
INFO
1
Checks
82 PASS 3 REVIEW 2 FIX
FCO2 Per Page LoadAction1.92g CO2 per viewFIX
CO2 Per Page Load
Action1.92g CO2 per view
1.92g CO2 per view
Warning::
1.92g CO2 per page view
This page transfers 8.1 MB, producing an estimated 1.92g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.05g, network 0.40g, end-user device 1.47g.
Got: 1.92g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 230.0 kg CO2/year
With 10,000 page views per month, this page would generate approximately 230.0 kg of CO2 annually — equivalent to charging 28755 smartphones.
Info::
Green hosting reduces data center emissions
1.92g
Carbon Footprint per page view
✗ Above sustainability target (0.50g)
Cleaner than 13% of websites
Sustainable Web Design model v4 · Page size: 8.1 MB
Your site
1.92g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.05g
Network
0.40g
End-user device
1.47g
At 10,000 monthly views: Monthly: 19.2 kg · Annual: 230.0 kg · ≈ 28755 smartphone charges
FCarbon BudgetAction87th percentileFIX
Carbon Budget
Action87th percentile
87th percentile
Warning::
1.92g CO2 — above the median website (0.60g)
Heavier than an estimated 13% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 87th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
1.92g
87th percentile
Cleaner than 13% of websites
✗ Above the median website
vs Median 220% more
vs Target 283% more
BGreen HostingGreen (hosting)REVIEW
Green Hosting
Green (hosting)
Green (hosting)
Info::
Cloudflare uses renewable energy
Info::
Cloudflare: Verified by the Green Web Foundation
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 Cloudflare✓CDN Shopify✗
Cloudflare: Verified by the Green Web Foundation
Based on known provider commitments. Verify at thegreenwebfoundation.org
BTransfer Efficiency88% efficientREVIEW
Transfer Efficiency
88% efficient
88% efficient
Info::
Transfer efficiency: 88%
An estimated 1018 KB (12%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 1018 KB of unused JavaScript. This wasted data produces 0.24g of unnecessary CO2 per page view.
Total waste: 1018 KB (12% of page weight)
Unused JS 1018 KB
0.24g unnecessary CO2 per visit
Actual transfer 8293 KB
Theoretical minimum 7275 KB
Potential savings 1018 KB (0.24g CO2)
See Deep Analysis sections above for specific optimizations.
BWeb Font Weight VariantsNo detectable Google Fonts weightsREVIEW
Web Font Weight Variants
No detectable Google Fonts weights
No detectable Google Fonts weights
Info::
No detectable Google Fonts weights
The analyzer detects font weights via Google Fonts URL parameters (~70% of font-using sites). Self-hosted fonts and non-Google CDN fonts aren't visible to URL-based detection. If you self-host fonts, manually audit how many @font-face weights you ship -- 2-3 weights per family is typically enough; 5+ is usually unused payload.
A+Repeat Visit Weight98% cachedPASS
Repeat Visit Weight
98% cached
98% cached
Info::
98% reduction on repeat visits
Returning visitors download only 155 KB (vs 8293 KB first visit). 365 of 368 resources are served from browser cache, saving 1.88g CO2 per repeat visit.
Info::
Repeat visit: 0.04g CO2 (first visit: 1.92g)
First visit
8293 KB
Repeat visit
155 KB
98% reduction on repeat visits
Saving 1.88g CO2 per returning visitor
365 resources served from cache · 3 resources re-downloaded
A+Green HostingWhether the site is served from green-energy infrastructurePASS
Green Hosting
Whether the site is served from green-energy infrastructure
Green Hosting
This site is hosted on green energy infrastructure
Provider: Cloudflare
Image Optimization1 images, 2 KB total, 1 KB wastedINFO
Image Optimization
1 images, 2 KB total, 1 KB wasted
Image Optimization Audit
Total Images
1
Total Size
2 KB
Oversized
1
Wasted
1 KB
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.