https://wan4ai.app
Sustainability
· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
98
GRADE
A+
FIX
0
REVIEW
1
PASS
6
INFO
1
Checks
86 PASS 1 REVIEW
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 Load0.29g CO2 per viewPASS
CO2 Per Page Load
0.29g CO2 per view
0.29g CO2 per view
Info::
0.29g CO2 per page view
This page transfers 1.2 MB, producing an estimated 0.29g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.01g, network 0.06g, end-user device 0.23g.
Got: 0.29g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 35.3 kg CO2/year
With 10,000 page views per month, this page would generate approximately 35.3 kg of CO2 annually — equivalent to charging 4413 smartphones.
Info::
Green hosting reduces data center emissions
0.29g
Carbon Footprint per page view
✓ Below sustainability target (0.50g)
Cleaner than 81% of websites
Sustainable Web Design model v4 · Page size: 1.2 MB
Your site
0.29g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.01g
Network
0.06g
End-user device
0.23g
At 10,000 monthly views: Monthly: 2.9 kg · Annual: 35.3 kg · ≈ 4413 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 Weight96% cachedPASS
Repeat Visit Weight
96% cached
96% cached
Info::
96% reduction on repeat visits
Returning visitors download only 48 KB (vs 1272 KB first visit). 86 of 87 resources are served from browser cache, saving 0.28g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.29g)
First visit
1272 KB
Repeat visit
48 KB
96% reduction on repeat visits
Saving 0.28g CO2 per returning visitor
86 resources served from cache · 1 resources re-downloaded
ACarbon Budget19th percentilePASS
Carbon Budget
19th percentile
19th percentile
Info::
0.29g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 81% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 19th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
0.29g
19th percentile
Cleaner than 81% of websites
✓ Below the Web Sustainability Guidelines target
vs Median 51% cleaner ✓
vs Target 41% cleaner ✓
A+Transfer Efficiency94% efficientPASS
Transfer Efficiency
94% efficient
94% efficient
Info::
Transfer efficiency: 94%
Only 74 KB of potential savings identified. Your page is well-optimized for size.
Total waste: 74 KB (6% of page weight)
Unused JS 74 KB
0.02g unnecessary CO2 per visit
Actual transfer 1272 KB
Theoretical minimum 1198 KB
Potential savings 74 KB (0.02g CO2)
See Deep Analysis sections above for specific optimizations.
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 Optimization4 images, 51 KB total, 23 KB wastedINFO
Image Optimization
4 images, 51 KB total, 23 KB wasted
Image Optimization Audit
Total Images
4
Total Size
51 KB
Oversized
1
Wasted
23 KB
1 missing lazy loading
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.