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 LoadAction2.13g CO2 per viewFIX
CO2 Per Page Load
Action2.13g CO2 per view
2.13g CO2 per view
Critical::
2.13g CO2 per page view
This page transfers 9.0 MB, producing an estimated 2.13g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.05g, network 0.44g, end-user device 1.63g.
Got: 2.13g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 255.1 kg CO2/year
With 10,000 page views per month, this page would generate approximately 255.1 kg of CO2 annually — equivalent to charging 31890 smartphones.
Info::
Green hosting reduces data center emissions
2.13g
Carbon Footprint per page view
✗ Above sustainability target (0.50g)
Cleaner than 5% of websites
Sustainable Web Design model v4 · Page size: 9.0 MB
Your site
2.13g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.05g
Network
0.44g
End-user device
1.63g
At 10,000 monthly views: Monthly: 21.3 kg · Annual: 255.1 kg · ≈ 31890 smartphone charges
FCarbon BudgetAction95th percentileFIX
Carbon Budget
Action95th percentile
95th percentile
Warning::
2.13g 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
2.13g
95th percentile
Cleaner than 5% of websites
✗ Above the median website
vs Median 254% more
vs Target 325% 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 Efficiency89% efficientREVIEW
Transfer Efficiency
89% efficient
89% efficient
Info::
Transfer efficiency: 89%
An estimated 1017 KB (11%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 1017 KB of unused JavaScript. This wasted data produces 0.24g of unnecessary CO2 per page view.
Total waste: 1017 KB (11% of page weight)
Unused JS 1017 KB
0.24g unnecessary CO2 per visit
Actual transfer 9197 KB
Theoretical minimum 8180 KB
Potential savings 1017 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 156 KB (vs 9197 KB first visit). 478 of 481 resources are served from browser cache, saving 2.09g CO2 per repeat visit.
Info::
Repeat visit: 0.04g CO2 (first visit: 2.13g)
First visit
9197 KB
Repeat visit
156 KB
98% reduction on repeat visits
Saving 2.09g CO2 per returning visitor
478 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.