https://www.spotify.com
Sustainability
· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
76
GRADE
C
FIX
2
REVIEW
1
PASS
3
INFO
0
Checks
63 PASS 1 REVIEW 2 FIX
DCO2 Per Page LoadAction1.06g CO2 per viewFIX
CO2 Per Page Load
Action1.06g CO2 per view
1.06g CO2 per view
Warning::
1.06g CO2 per page view
This page transfers 4.5 MB, producing an estimated 1.06g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.03g, network 0.22g, end-user device 0.81g.
Got: 1.06g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 126.7 kg CO2/year
With 10,000 page views per month, this page would generate approximately 126.7 kg of CO2 annually — equivalent to charging 15833 smartphones.
Info::
Green hosting reduces data center emissions
1.06g
Carbon Footprint per page view
✗ Above sustainability target (0.50g)
Cleaner than 37% of websites
Sustainable Web Design model v4 · Page size: 4.5 MB
Your site
1.06g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.03g
Network
0.22g
End-user device
0.81g
At 10,000 monthly views: Monthly: 10.6 kg · Annual: 126.7 kg · ≈ 15833 smartphone charges
DCarbon BudgetAction63th percentileFIX
Carbon Budget
Action63th percentile
63th percentile
Warning::
1.06g CO2 — above the median website (0.60g)
Heavier than an estimated 37% of websites. Reducing page weight, optimizing images, and removing unused JavaScript would lower the carbon footprint. See the Performance tab.
Info::
Estimated 63th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
1.06g
63rd percentile
Cleaner than 37% of websites
✗ Above the median website
vs Median 76% more
vs Target 111% more
BTransfer Efficiency87% efficientREVIEW
Transfer Efficiency
87% efficient
87% efficient
Info::
Transfer efficiency: 87%
An estimated 594 KB (13%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 594 KB of unused JavaScript. This wasted data produces 0.14g of unnecessary CO2 per page view.
Total waste: 594 KB (13% of page weight)
Unused JS 594 KB
0.14g unnecessary CO2 per visit
Actual transfer 4566 KB
Theoretical minimum 3972 KB
Potential savings 594 KB (0.14g 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: Google Cloud, CDN: Fastly
Info::
Google Cloud: Verified by the Green Web Foundation
Info::
Fastly: 100% renewable energy for edge network
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 Google Cloud✓CDN Fastly✓
Google Cloud: Verified by the Green Web Foundation
Fastly: 100% renewable energy for edge network
Based on known provider commitments. Verify at thegreenwebfoundation.org
A+Repeat Visit Weight100% cachedPASS
Repeat Visit Weight
100% cached
100% cached
Info::
100% reduction on repeat visits
Returning visitors download only 22 KB (vs 4566 KB first visit). 151 of 152 resources are served from browser cache, saving 1.05g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 1.06g)
First visit
4566 KB
Repeat visit
22 KB
100% reduction on repeat visits
Saving 1.05g CO2 per returning visitor
151 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: Google Cloud
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.