https://rasterbator.org
Sustainability
· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
86
GRADE
B
FIX
0
REVIEW
3
PASS
4
INFO
1
Checks
84 PASS 3 REVIEW
BCarbon Budget32th percentileREVIEW
Carbon Budget
32th percentile
32th percentile
Info::
0.43g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 68% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 32th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
0.43g
32nd percentile
Cleaner than 68% of websites
✓ Below the Web Sustainability Guidelines target
vs Median 29% cleaner ✓
vs Target 14% cleaner ✓
BTransfer Efficiency80% efficientREVIEW
Transfer Efficiency
80% efficient
80% efficient
Info::
Transfer efficiency: 80%
An estimated 378 KB (20%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 378 KB of unused JavaScript. This wasted data produces 0.09g of unnecessary CO2 per page view.
Total waste: 378 KB (20% of page weight)
Unused JS 378 KB
0.09g unnecessary CO2 per visit
Actual transfer 1853 KB
Theoretical minimum 1475 KB
Potential savings 378 KB (0.09g 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.
ACO2 Per Page Load0.43g CO2 per viewPASS
CO2 Per Page Load
0.43g CO2 per view
0.43g CO2 per view
Info::
0.43g CO2 per page view
This page transfers 1.8 MB, producing an estimated 0.43g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.01g, network 0.09g, end-user device 0.33g.
Got: 0.43g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 51.4 kg CO2/year
With 10,000 page views per month, this page would generate approximately 51.4 kg of CO2 annually — equivalent to charging 6427 smartphones.
Info::
Green hosting reduces data center emissions
0.43g
Carbon Footprint per page view
✓ Below sustainability target (0.50g)
Cleaner than 68% of websites
Sustainable Web Design model v4 · Page size: 1.8 MB
Your site
0.43g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.01g
Network
0.09g
End-user device
0.33g
At 10,000 monthly views: Monthly: 4.3 kg · Annual: 51.4 kg · ≈ 6427 smartphone charges
A+Green HostingGreen (both)PASS
Green Hosting
Green (both)
Green (both)
Info::
Both hosting and CDN use renewable energy
Got: Hosting: Next.js, CDN: Cloudflare
Info::
Next.js: 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 Next.js✓CDN Cloudflare✓
Next.js: 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 Weight90% cachedPASS
Repeat Visit Weight
90% cached
90% cached
Info::
90% reduction on repeat visits
Returning visitors download only 178 KB (vs 1853 KB first visit). 110 of 121 resources are served from browser cache, saving 0.39g CO2 per repeat visit.
Info::
Repeat visit: 0.04g CO2 (first visit: 0.43g)
First visit
1853 KB
Repeat visit
178 KB
90% reduction on repeat visits
Saving 0.39g CO2 per returning visitor
110 resources served from cache · 11 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
Image Optimization34 images, 216 KB total, 81 KB wastedINFO
Image Optimization
34 images, 216 KB total, 81 KB wasted
Image Optimization Audit
Total Images
34
Total Size
216 KB
Oversized
8
Wasted
81 KB
26 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.