https://timelinevisualizer.org
Sustainability
· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
87
GRADE
B
FIX
0
REVIEW
3
PASS
4
INFO
1
Checks
84 PASS 3 REVIEW
BTransfer Efficiency84% efficientREVIEW
Transfer Efficiency
84% efficient
84% efficient
Info::
Transfer efficiency: 84%
An estimated 153 KB (16%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 153 KB of unused JavaScript. This wasted data produces 0.04g of unnecessary CO2 per page view.
Total waste: 153 KB (16% of page weight)
Unused JS 153 KB
0.04g unnecessary CO2 per visit
Actual transfer 969 KB
Theoretical minimum 815 KB
Potential savings 153 KB (0.04g 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.
CGreen HostingActionWhether the site is served from green-energy infrastructureREVIEW
Green Hosting
ActionWhether the site is served from green-energy infrastructure
Green Hosting
No green hosting detected
ACO2 Per Page Load0.22g CO2 per viewPASS
CO2 Per Page Load
0.22g CO2 per view
0.22g CO2 per view
Info::
0.22g CO2 per page view
This page transfers 0.9 MB, producing an estimated 0.22g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.01g, network 0.05g, end-user device 0.17g.
Got: 0.22g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 26.9 kg CO2/year
With 10,000 page views per month, this page would generate approximately 26.9 kg of CO2 annually — equivalent to charging 3360 smartphones.
Info::
Green hosting reduces data center emissions
0.22g
Carbon Footprint per page view
✓ Below sustainability target (0.50g)
Cleaner than 88% of websites
Sustainable Web Design model v4 · Page size: 0.9 MB
Your site
0.22g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.01g
Network
0.05g
End-user device
0.17g
At 10,000 monthly views: Monthly: 2.2 kg · Annual: 26.9 kg · ≈ 3360 smartphone charges
AGreen HostingGreen (cdn)PASS
Green Hosting
Green (cdn)
Green (cdn)
Info::
Cloudflare CDN uses renewable energy
Since most traffic is served through the CDN, the majority of data transfer energy is renewable.
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 Not identified✗CDN Cloudflare✓
Cloudflare: 100% renewable energy for global network since 2019
Based on known provider commitments. Verify at thegreenwebfoundation.org
A+Repeat Visit Weight98% cachedPASS
Repeat Visit Weight
98% cached
98% cached
Info::
98% reduction on repeat visits
Returning visitors download only 15 KB (vs 969 KB first visit). 67 of 68 resources are served from browser cache, saving 0.22g CO2 per repeat visit.
Info::
Repeat visit: 0.00g CO2 (first visit: 0.22g)
First visit
969 KB
Repeat visit
15 KB
98% reduction on repeat visits
Saving 0.22g CO2 per returning visitor
67 resources served from cache · 1 resources re-downloaded
ACarbon Budget12th percentilePASS
Carbon Budget
12th percentile
12th percentile
Info::
0.22g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 88% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 12th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
0.22g
12th percentile
Cleaner than 88% of websites
✓ Below the Web Sustainability Guidelines target
vs Median 63% cleaner ✓
vs Target 55% cleaner ✓
Image Optimization4 images, 144 KB total, 0 KB wastedINFO
Image Optimization
4 images, 144 KB total, 0 KB wasted
Image Optimization Audit
Total Images
4
Total Size
144 KB
2 missing dimensions 2 missing lazy loading
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.