https://usort.co
Sustainability
· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
93
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 Load0.33g CO2 per viewPASS
CO2 Per Page Load
0.33g CO2 per view
0.33g CO2 per view
Info::
0.33g CO2 per page view
This page transfers 1.4 MB, producing an estimated 0.33g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.01g, network 0.07g, end-user device 0.25g.
Got: 0.33g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 39.6 kg CO2/year
With 10,000 page views per month, this page would generate approximately 39.6 kg of CO2 annually — equivalent to charging 4945 smartphones.
Info::
Green hosting reduces data center emissions
0.33g
Carbon Footprint per page view
✓ Below sustainability target (0.50g)
Cleaner than 78% of websites
Sustainable Web Design model v4 · Page size: 1.4 MB
Your site
0.33g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.01g
Network
0.07g
End-user device
0.25g
At 10,000 monthly views: Monthly: 3.3 kg · Annual: 39.6 kg · ≈ 4945 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 Weight98% cachedPASS
Repeat Visit Weight
98% cached
98% cached
Info::
98% reduction on repeat visits
Returning visitors download only 21 KB (vs 1426 KB first visit). 81 of 82 resources are served from browser cache, saving 0.32g CO2 per repeat visit.
Info::
Repeat visit: 0.01g CO2 (first visit: 0.33g)
First visit
1426 KB
Repeat visit
21 KB
98% reduction on repeat visits
Saving 0.32g CO2 per returning visitor
81 resources served from cache · 1 resources re-downloaded
ACarbon Budget22th percentilePASS
Carbon Budget
22th percentile
22th percentile
Info::
0.33g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 78% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 22th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
0.33g
22nd percentile
Cleaner than 78% of websites
✓ Below the Web Sustainability Guidelines target
vs Median 45% cleaner ✓
vs Target 34% cleaner ✓
A+Transfer Efficiency98% efficientPASS
Transfer Efficiency
98% efficient
98% efficient
Info::
Transfer efficiency: 98%
Only 24 KB of potential savings identified. Your page is well-optimized for size.
Total waste: 24 KB (2% of page weight)
Unused JS 24 KB
0.01g unnecessary CO2 per visit
Actual transfer 1426 KB
Theoretical minimum 1401 KB
Potential savings 24 KB (0.01g 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 Optimization39 images, 50 KB total, 0 KB wastedINFO
Image Optimization
39 images, 50 KB total, 0 KB wasted
Image Optimization Audit
Total Images
39
Total Size
50 KB
3 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.