https://calendly.com
Sustainability
· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
68
GRADE
D
FIX
3
REVIEW
0
PASS
3
INFO
0
Checks
63 PASS 3 FIX
DCO2 Per Page LoadAction0.85g CO2 per viewFIX
CO2 Per Page Load
Action0.85g CO2 per view
0.85g CO2 per view
Info::
0.85g CO2 per page view
This page transfers 3.6 MB, producing an estimated 0.85g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.02g, network 0.18g, end-user device 0.66g.
Got: 0.85g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 102.5 kg CO2/year
With 10,000 page views per month, this page would generate approximately 102.5 kg of CO2 annually — equivalent to charging 12809 smartphones.
Info::
Green hosting reduces data center emissions
0.85g
Carbon Footprint per page view
✗ Above sustainability target (0.50g)
Cleaner than 43% of websites
Sustainable Web Design model v4 · Page size: 3.6 MB
Your site
0.85g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.02g
Network
0.18g
End-user device
0.66g
At 10,000 monthly views: Monthly: 8.5 kg · Annual: 102.5 kg · ≈ 12809 smartphone charges
DCarbon BudgetAction57th percentileFIX
Carbon Budget
Action57th percentile
57th percentile
Warning::
0.85g CO2 — above the median website (0.60g)
Heavier than an estimated 43% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 57th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
0.85g
57th percentile
Cleaner than 43% of websites
✗ Above the median website
vs Median 42% more
vs Target 71% more
DTransfer EfficiencyAction57% efficientFIX
Transfer Efficiency
Action57% efficient
57% efficient
Warning::
Transfer efficiency: 57%
An estimated 1577 KB (43%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 1577 KB of unused JavaScript. This wasted data produces 0.36g of unnecessary CO2 per page view.
Total waste: 1577 KB (43% of page weight)
Unused JS 1577 KB
0.36g unnecessary CO2 per visit
Actual transfer 3694 KB
Theoretical minimum 2117 KB
Potential savings 1577 KB (0.36g CO2)
See Deep Analysis sections above for specific optimizations.
A+Green HostingGreen (both)PASS
Green Hosting
Green (both)
Green (both)
Info::
Both hosting and CDN use renewable energy
Got: Hosting: AWS, CDN: Cloudflare
Info::
AWS: Verified by the Green Web Foundation
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 AWS✓CDN Cloudflare✓
AWS: Verified by the Green Web Foundation
Cloudflare: 100% renewable energy for global network since 2019
Based on known provider commitments. Verify at thegreenwebfoundation.org
A+Repeat Visit Weight85% cachedPASS
Repeat Visit Weight
85% cached
85% cached
Info::
85% reduction on repeat visits
Returning visitors download only 538 KB (vs 3694 KB first visit). 155 of 156 resources are served from browser cache, saving 0.73g CO2 per repeat visit.
Info::
Repeat visit: 0.12g CO2 (first visit: 0.85g)
First visit
3694 KB
Repeat visit
538 KB
85% reduction on repeat visits
Saving 0.73g CO2 per returning visitor
155 resources served from cache · 1 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
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.