Core Web Vitals Fixer
Your LCP is 4 seconds, CLS keeps jumping, and FID feels sluggish. This tool scans your code and tells you exactly what to fix and how.
One command. Zero config. Just works.
Quick Start
npx ai-core-vitals ./src/
What It Does
- Analyzes your code for Core Web Vitals issues
- Identifies LCP, FID, and CLS problems
- Provides specific fixes with code examples
- Prioritizes issues by impact
Usage Examples
# Scan your source directory
npx ai-core-vitals ./src/
# Scan app directory
npx ai-core-vitals ./app/
# Focus on specific metric
npx ai-core-vitals ./src/ --metric lcp
Best Practices
- Fix LCP first - it's usually the biggest win
- Lazy load below the fold - don't load what users can't see
- Reserve space for images - prevents CLS
- Defer non-critical JS - improves FID
When to Use This
- Lighthouse scores are tanking your SEO
- Users complain about slow page loads
- Core Web Vitals failing in Search Console
- Building a new site and want to start optimized
Part of the LXGIC Dev Toolkit
This is one of 110+ free developer tools built by LXGIC Studios. No paywalls, no sign-ups, no API keys on free tiers. Just tools that work.
Find more:
- GitHub: https://github.com/LXGIC-Studios
- Twitter: https://x.com/lxgicstudios
- Substack: https://lxgicstudios.substack.com
- Website: https://lxgicstudios.com
Requirements
No install needed. Just run with npx. Node.js 18+ recommended. Needs OPENAI_API_KEY environment variable.
npx ai-core-vitals --help
How It Works
Scans your code files for common performance antipatterns, then sends them to GPT-4o-mini. The AI identifies issues affecting LCP, CLS, and FID and provides actionable fixes with priority rankings.
License
MIT. Free forever. Use it however you want.