Sustainability

· 8 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.

SCORE

GRADE

FIX

REVIEW

PASS

INFO

Device:

Mobile Desktop

Checks

4 PASS 3 REVIEW

Transfer Efficiency

Action

71% efficient

REVIEW

71% efficient

Transfer efficiency: 71%

An estimated 407 KB (29%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 407 KB of unused JavaScript. This wasted data produces 0.09g of unnecessary CO2 per page view.

Total waste: 407 KB (29% of page weight)

Unused JS 407 KB

0.09g unnecessary CO2 per visit

Actual transfer 1412 KB

Theoretical minimum 1004 KB

Potential savings 407 KB (0.09g CO2)

See Deep Analysis sections above for specific optimizations.

Web Font Weight Variants

No detectable Google Fonts weights

REVIEW

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.

Green Hosting

Action

Whether the site is served from green-energy infrastructure

REVIEW

Green Hosting

No green hosting detected

CO2 Per Page Load

0.33g CO2 per view

PASS

0.33g CO2 per view

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)

At 10,000 monthly views: 39.2 kg CO2/year

With 10,000 page views per month, this page would generate approximately 39.2 kg of CO2 annually — equivalent to charging 4896 smartphones.

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: 39.2 kg · ≈ 4896 smartphone charges

Green Hosting

Green (cdn)

PASS

Green (cdn)

Netlify CDN uses renewable energy

Since most traffic is served through the CDN, the majority of data transfer energy is renewable.

Netlify: Hosted on AWS/Google Cloud with renewable energy matching

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 Netlify✓

Netlify: Hosted on AWS/Google Cloud with renewable energy matching

Based on known provider commitments. Verify at thegreenwebfoundation.org

A+

Repeat Visit Weight

92% cached

PASS

92% cached

92% reduction on repeat visits

Returning visitors download only 114 KB (vs 1412 KB first visit). 106 of 117 resources are served from browser cache, saving 0.30g CO2 per repeat visit.

Repeat visit: 0.03g CO2 (first visit: 0.33g)

First visit

1412 KB

Repeat visit

114 KB

92% reduction on repeat visits

Saving 0.30g CO2 per returning visitor

106 resources served from cache · 11 resources re-downloaded

Carbon Budget

22th percentile

PASS

22th percentile

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.

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 46% cleaner ✓

vs Target 35% cleaner ✓

Image Optimization

5 images, 298 KB total, 148 KB wasted

INFO

Image Optimization Audit

Total Images

Total Size

298 KB

Oversized

Wasted

148 KB

5 missing dimensions 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.