https://samplab.pro
Sustainability
· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.SCORE
95
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 Load0.21g CO2 per viewPASS
CO2 Per Page Load
0.21g CO2 per view
0.21g CO2 per view
Info::
0.21g CO2 per page view
This page transfers 0.9 MB, producing an estimated 0.21g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.01g, network 0.04g, end-user device 0.16g.
Got: 0.21g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 25.1 kg CO2/year
With 10,000 page views per month, this page would generate approximately 25.1 kg of CO2 annually — equivalent to charging 3136 smartphones.
Info::
Green hosting reduces data center emissions
0.21g
Carbon Footprint per page view
✓ Below sustainability target (0.50g)
Cleaner than 90% of websites
Sustainable Web Design model v4 · Page size: 0.9 MB
Your site
0.21g
Top 10%
0.20g
Target
0.50g
Median website
0.60g
Energy Breakdown
Data center
0.01g
Network
0.04g
End-user device
0.16g
At 10,000 monthly views: Monthly: 2.1 kg · Annual: 25.1 kg · ≈ 3136 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 Weight99% cachedPASS
Repeat Visit Weight
99% cached
99% cached
Info::
99% reduction on repeat visits
Returning visitors download only 7 KB (vs 904 KB first visit). 57 of 58 resources are served from browser cache, saving 0.21g CO2 per repeat visit.
Info::
Repeat visit: 0.00g CO2 (first visit: 0.21g)
First visit
904 KB
Repeat visit
7 KB
99% reduction on repeat visits
Saving 0.21g CO2 per returning visitor
57 resources served from cache · 1 resources re-downloaded
A+Carbon Budget10th percentilePASS
Carbon Budget
10th percentile
10th percentile
Info::
0.21g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 90% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 10th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website
0.21g
10th percentile
Cleaner than 90% of websites
✓ Below the Web Sustainability Guidelines target
vs Median 65% cleaner ✓
vs Target 58% cleaner ✓
A+Transfer Efficiency95% efficientPASS
Transfer Efficiency
95% efficient
95% efficient
Info::
Transfer efficiency: 95%
Only 46 KB of potential savings identified. Your page is well-optimized for size.
Total waste: 46 KB (5% of page weight)
Unused JS 46 KB
0.01g unnecessary CO2 per visit
Actual transfer 904 KB
Theoretical minimum 858 KB
Potential savings 46 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 Optimization15 images, 29 KB total, 0 KB wastedINFO
Image Optimization
15 images, 29 KB total, 0 KB wasted
Image Optimization Audit
Total Images
15
Total Size
29 KB
9 missing dimensions
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.