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

5 PASS 2 REVIEW

Transfer Efficiency

88% efficient

REVIEW

88% efficient

Transfer efficiency: 88%

An estimated 121 KB (12%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 121 KB of unused JavaScript. This wasted data produces 0.03g of unnecessary CO2 per page view.

Total waste: 121 KB (12% of page weight)

Unused JS 121 KB

0.03g unnecessary CO2 per visit

Actual transfer 1020 KB

Theoretical minimum 899 KB

Potential savings 121 KB (0.03g 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.

CO2 Per Page Load

0.24g CO2 per view

PASS

0.24g CO2 per view

0.24g CO2 per page view

This page transfers 1.0 MB, producing an estimated 0.24g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.01g, network 0.05g, end-user device 0.18g.

Got: 0.24g CO2 Expected: < 0.50g (sustainability target)

At 10,000 monthly views: 28.3 kg CO2/year

With 10,000 page views per month, this page would generate approximately 28.3 kg of CO2 annually — equivalent to charging 3537 smartphones.

Green hosting reduces data center emissions

0.24g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 87% of websites

Sustainable Web Design model v4 · Page size: 1.0 MB

Your site

0.24g

Top 10%

0.20g

Target

0.50g

Median website

0.60g

Energy Breakdown

Data center

0.01g

Network

0.05g

End-user device

0.18g

At 10,000 monthly views: Monthly: 2.4 kg · Annual: 28.3 kg · ≈ 3537 smartphone charges

A+

Green Hosting

Green (both)

PASS

Green (both)

Both hosting and CDN use renewable energy

Got: Hosting: Next.js, CDN: Cloudflare

Next.js: Verified by the Green Web Foundation

Cloudflare: 100% renewable energy for global network since 2019

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 Weight

96% cached

PASS

96% cached

96% reduction on repeat visits

Returning visitors download only 38 KB (vs 1020 KB first visit). 37 of 38 resources are served from browser cache, saving 0.23g CO2 per repeat visit.

Repeat visit: 0.01g CO2 (first visit: 0.24g)

First visit

1020 KB

Repeat visit

38 KB

96% reduction on repeat visits

Saving 0.23g CO2 per returning visitor

37 resources served from cache · 1 resources re-downloaded

Carbon Budget

13th percentile

PASS

13th percentile

0.24g CO2 — below the sustainability target of 0.50g

Cleaner than an estimated 87% of websites analyzed. This page meets the Web Sustainability Guidelines target.

Estimated 13th percentile

Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.

Top 10%

Target

Median website

0.24g

13th percentile

Cleaner than 87% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 61% cleaner ✓

vs Target 53% cleaner ✓

A+

Green Hosting

Whether the site is served from green-energy infrastructure

PASS

Green Hosting

This site is hosted on green energy infrastructure

Provider: Cloudflare

Image Optimization

20 images, 378 KB total, 222 KB wasted

INFO

Image Optimization Audit

Total Images

Total Size

378 KB

Oversized

Wasted

222 KB

10 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.