https://freesound.org
Sustainability
· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
88
GRADE
B
FIX
0
REVIEW
2
PASS
4
INFO
0
Checks
64 PASS 2 REVIEW
BGreen HostingGreen (hosting)REVIEW
Green Hosting
Green (hosting)
Green (hosting)
Info::
Hetzner Online GmbH uses renewable energy
Info::
Hetzner Online GmbH: 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 Hetzner Online GmbH✓CDN Not identified✗
Hetzner Online GmbH: Verified by the Green Web Foundation
Based on known provider commitments. Verify at thegreenwebfoundation.org
CTransfer EfficiencyAction67% efficientREVIEW
Transfer Efficiency
Action67% efficient
67% efficient
Warning::
Transfer efficiency: 67%
An estimated 205 KB (33%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 205 KB of unused JavaScript. This wasted data produces 0.05g of unnecessary CO2 per page view.
Total waste: 205 KB (33% of page weight)
Unused JS 205 KB
0.05g unnecessary CO2 per visit
Actual transfer 627 KB
Theoretical minimum 421 KB
Potential savings 205 KB (0.05g CO2)
See Deep Analysis sections above for specific optimizations.
A+CO2 Per Page Load0.15g CO2 per viewPASS
CO2 Per Page Load
0.15g CO2 per view
0.15g CO2 per view
Info::
0.15g CO2 per page view
This page transfers 0.6 MB, producing an estimated 0.15g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.00g, network 0.03g, end-user device 0.11g.
Got: 0.15g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 17.4 kg CO2/year
With 10,000 page views per month, this page would generate approximately 17.4 kg of CO2 annually — equivalent to charging 2175 smartphones.
Info::
Green hosting reduces data center emissions
0.15g
Carbon Footprint per page view
✓ Below sustainability target (0.50g)
Cleaner than 90% of websites
Sustainable Web Design model v4 · Page size: 0.6 MB
Your site
0.15g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.00g
Network
0.03g
End-user device
0.11g
At 10,000 monthly views: Monthly: 1.5 kg · Annual: 17.4 kg · ≈ 2175 smartphone charges
A+Repeat Visit Weight92% cachedPASS
Repeat Visit Weight
92% cached
92% cached
Info::
92% reduction on repeat visits
Returning visitors download only 51 KB (vs 627 KB first visit). 46 of 47 resources are served from browser cache, saving 0.13g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.15g)
First visit
627 KB
Repeat visit
51 KB
92% reduction on repeat visits
Saving 0.13g CO2 per returning visitor
46 resources served from cache · 1 resources re-downloaded
A+Carbon Budget10th percentilePASS
Carbon Budget
10th percentile
10th percentile
Info::
0.15g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 90% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 10th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
0.15g
10th percentile
Cleaner than 90% of websites
✓ Below the Web Sustainability Guidelines target
vs Median 76% cleaner ✓
vs Target 71% cleaner ✓
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: Hetzner Online GmbH
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.