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

Green Hosting

Green (hosting)

REVIEW

Green (hosting)

Next.js uses renewable energy

Next.js: Verified by the Green Web Foundation

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 Not identified✗

Next.js: Verified by the Green Web Foundation

Based on known provider commitments. Verify at thegreenwebfoundation.org

Transfer Efficiency

86% efficient

REVIEW

86% efficient

Transfer efficiency: 86%

An estimated 190 KB (14%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 190 KB of unused JavaScript. This wasted data produces 0.04g of unnecessary CO2 per page view.

Total waste: 190 KB (14% of page weight)

Unused JS 190 KB

0.04g unnecessary CO2 per visit

Actual transfer 1367 KB

Theoretical minimum 1177 KB

Potential savings 190 KB (0.04g 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

0.32g CO2 per view

PASS

0.32g CO2 per view

0.32g CO2 per page view

This page transfers 1.3 MB, producing an estimated 0.32g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.01g, network 0.07g, end-user device 0.24g.

Got: 0.32g CO2 Expected: < 0.50g (sustainability target)

At 10,000 monthly views: 37.9 kg CO2/year

With 10,000 page views per month, this page would generate approximately 37.9 kg of CO2 annually — equivalent to charging 4742 smartphones.

Green hosting reduces data center emissions

0.32g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 79% of websites

Sustainable Web Design model v4 · Page size: 1.3 MB

Your site

0.32g

Top 10%

0.20g

Target

0.50g

Median website

0.60g

Energy Breakdown

Data center

0.01g

Network

0.07g

End-user device

0.24g

At 10,000 monthly views: Monthly: 3.2 kg · Annual: 37.9 kg · ≈ 4742 smartphone charges

A+

Repeat Visit Weight

91% cached

PASS

91% cached

91% reduction on repeat visits

Returning visitors download only 129 KB (vs 1367 KB first visit). 42 of 43 resources are served from browser cache, saving 0.29g CO2 per repeat visit.

Repeat visit: 0.03g CO2 (first visit: 0.32g)

First visit

1367 KB

Repeat visit

129 KB

91% reduction on repeat visits

Saving 0.29g CO2 per returning visitor

42 resources served from cache · 1 resources re-downloaded

Carbon Budget

21th percentile

PASS

21th percentile

0.32g CO2 — below the sustainability target of 0.50g

Cleaner than an estimated 79% of websites analyzed. This page meets the Web Sustainability Guidelines target.

Estimated 21th percentile

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

Top 10%

Target

Median website

0.32g

21st percentile

Cleaner than 79% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 47% cleaner ✓

vs Target 37% 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: Infomaniak

Image Optimization

11 images, 148 KB total, 44 KB wasted

INFO

Image Optimization Audit

Total Images

Total Size

148 KB

Oversized

Wasted

44 KB

8 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.