https://www.youtube.com
Sustainability
· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
76
GRADE
C
FIX
1
REVIEW
2
PASS
4
INFO
1
Checks
84 PASS 2 REVIEW 1 FIX
DTransfer EfficiencyAction53% efficientFIX
Transfer Efficiency
Action53% efficient
53% efficient
Warning::
Transfer efficiency: 53%
An estimated 618 KB (47%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 618 KB of unused JavaScript. This wasted data produces 0.14g of unnecessary CO2 per page view.
Total waste: 618 KB (47% of page weight)
Unused JS 618 KB
0.14g unnecessary CO2 per visit
Actual transfer 1325 KB
Theoretical minimum 707 KB
Potential savings 618 KB (0.14g CO2)
See Deep Analysis sections above for specific optimizations.
BGreen HostingGreen (hosting)REVIEW
Green Hosting
Green (hosting)
Green (hosting)
Info::
Google Cloud uses renewable energy
Info::
Google Cloud: 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 Google Cloud✓CDN Not identified✗
Google Cloud: Verified by the Green Web Foundation
Based on known provider commitments. Verify at thegreenwebfoundation.org
CWeb Font Weight VariantsAction10 font weights loaded across 3 famil(y/ies)REVIEW
Web Font Weight Variants
Action10 font weights loaded across 3 famil(y/ies)
10 font weights loaded across 3 famil(y/ies)
Warning::
10 font weights loaded -- likely 100+ KB of unused payload
Loading 10 font weights typically transfers 200-400 KB just for fonts. Most pages legitimately use 2-3 weights (regular + bold, maybe medium). Audit which weights your stylesheet actually applies and trim the Google Fonts URL accordingly. Affected families: Roboto, Roboto Mono, YouTube Sans.
ACO2 Per Page Load0.31g CO2 per viewPASS
CO2 Per Page Load
0.31g CO2 per view
0.31g CO2 per view
Info::
0.31g CO2 per page view
This page transfers 1.3 MB, producing an estimated 0.31g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.01g, network 0.06g, end-user device 0.24g.
Got: 0.31g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 36.8 kg CO2/year
With 10,000 page views per month, this page would generate approximately 36.8 kg of CO2 annually — equivalent to charging 4596 smartphones.
Info::
Green hosting reduces data center emissions
0.31g
Carbon Footprint per page view
✓ Below sustainability target (0.50g)
Cleaner than 80% of websites
Sustainable Web Design model v4 · Page size: 1.3 MB
Your site
0.31g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.01g
Network
0.06g
End-user device
0.24g
At 10,000 monthly views: Monthly: 3.1 kg · Annual: 36.8 kg · ≈ 4596 smartphone charges
A+Repeat Visit Weight95% cachedPASS
Repeat Visit Weight
95% cached
95% cached
Info::
95% reduction on repeat visits
Returning visitors download only 63 KB (vs 1325 KB first visit). 70 of 72 resources are served from browser cache, saving 0.29g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.31g)
First visit
1325 KB
Repeat visit
63 KB
95% reduction on repeat visits
Saving 0.29g CO2 per returning visitor
70 resources served from cache · 2 resources re-downloaded
ACarbon Budget20th percentilePASS
Carbon Budget
20th percentile
20th percentile
Info::
0.31g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 80% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 20th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
0.31g
20th percentile
Cleaner than 80% of websites
✓ Below the Web Sustainability Guidelines target
vs Median 49% cleaner ✓
vs Target 39% 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: Google Cloud
Image Optimization7 images, 0 KB total, 0 KB wastedINFO
Image Optimization
7 images, 0 KB total, 0 KB wasted
Image Optimization Audit
Total Images
7
Total Size
0 KB
7 missing alt text 7 missing dimensions 7 missing lazy loading
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.