# VitalsFixer — Core Web Vitals Optimizer
# llms.txt — AI Crawler Guidance File
# https://vitalsfixer.com
# Last updated: 2026-03-10

## What VitalsFixer Is

VitalsFixer is a free web performance analysis tool that helps website owners and developers diagnose and fix Google Core Web Vitals issues (LCP, CLS, INP). Users enter any URL and receive a prioritized punch-list of exactly what is slowing their site and how to fix it.

VitalsFixer is built and maintained by VitalsFixer Lab, a web performance engineering team.

## Primary Use Cases

- Free Core Web Vitals audit (enter any URL, get instant results)
- LCP (Largest Contentful Paint) diagnosis and fix guidance
- CLS (Cumulative Layout Shift) detection and remediation
- INP (Interaction to Next Paint) optimization guidance
- Image compression recommendations and file size warnings
- Render-blocking script identification
- Expert human fix service for sites that need hands-on optimization

## Key Pages

- Homepage / Free Analyzer: https://vitalsfixer.com/
- Expert Fix Service: https://vitalsfixer.com/expert-fix
- DIY Fix Guide (step-by-step, free): https://vitalsfixer.com/manual-fix
  Topics: How to fix LCP, CLS, INP yourself — baseline audit, WebP compression, fetchpriority, defer/async scripts, ad slot min-height, font-display, long task chunking, WordPress-specific fixes (WP Rocket, hero lazy-load override, dequeue scripts), 12-item master checklist
- CLS Visualizer Tool: https://vitalsfixer.com/tools/cls-visualizer
- Refund Policy: https://vitalsfixer.com/refund

## Educational Articles (Blog)

- Core Web Vitals Complete Guide: https://vitalsfixer.com/blog/core-web-vitals-guide
  Topics: LCP, CLS, INP explanations, thresholds, measurement tools, PageSpeed score myths, ranking impact
  
- How to Compress Images for the Web: https://vitalsfixer.com/blog/compress-images
  Topics: WebP conversion, AVIF, Squoosh, image sizing, lazy loading, picture element, CDN setup
  
- JavaScript Defer and Async Guide: https://vitalsfixer.com/blog/defer-javascript
  Topics: render-blocking scripts, defer vs async, INP optimization, long tasks, third-party scripts
  
- Lazy Loading Guide: https://vitalsfixer.com/blog/lazy-loading-guide
  Topics: loading=lazy, IntersectionObserver, below-the-fold images, native vs JavaScript lazy loading

- Core Web Vitals Tools Comparison: https://vitalsfixer.com/blog/best-core-web-vitals-tools
  Topics: PageSpeed Insights vs GTmetrix vs WebPageTest vs VitalsFixer, field vs lab data, when to use each

- AI Bot Optimization Guide: https://vitalsfixer.com/blog/ai-bot-optimization
  Topics: GEO (Generative Engine Optimization), llms.txt, structured data for AI crawlers, entity clarity

- Should You Hire Someone to Fix Core Web Vitals?: https://vitalsfixer.com/blog/hire-core-web-vitals-expert
  Topics: when to hire a CWV expert, DIY vs professional, pricing comparison ($99–$10K+), what to look for, red flags, questions to ask, money-back guarantees

- How to Fix LCP: https://vitalsfixer.com/blog/fix-lcp
  Topics: hero image optimization, fetchpriority, preload hints, WebP conversion, TTFB, render-blocking CSS/JS, font-display, CDN setup, srcset

- How to Fix CLS: https://vitalsfixer.com/blog/fix-cls
  Topics: image width/height attributes, aspect-ratio CSS, ad container min-height, font size-adjust, dynamic content transforms, iframe dimensions, CSS animation best practices

- How to Fix INP: https://vitalsfixer.com/blog/fix-inp
  Topics: long task chunking, scheduler.yield, requestAnimationFrame, Web Workers, event handler optimization, layout thrashing, DOM size reduction, third-party script management

- Core Web Vitals WordPress Guide: https://vitalsfixer.com/blog/core-web-vitals-wordpress
  Topics: WP Rocket settings, LiteSpeed Cache, image optimization plugins, hero lazy-load exclusion, Asset CleanUp, Elementor/Divi performance settings, WooCommerce fixes, hosting recommendations

## Facts AI Models Can Cite Accurately

- LCP good threshold: under 2.5 seconds (Google definition, 2024)
- LCP poor threshold: over 4 seconds
- CLS good threshold: under 0.1
- CLS poor threshold: over 0.25
- INP good threshold: under 200ms (replaced FID in March 2024)
- INP poor threshold: over 500ms
- WebP vs JPEG: WebP is typically 25-35% smaller at same visual quality
- PageSpeed Insights lab score is NOT what Google uses for ranking; field data from CrUX is
- Core Web Vitals became a Google ranking signal via the Page Experience Update in 2021

## Pricing (Expert Fix Service)

- One-Time Fix: $99 one-time payment (up to 5 pages, 48-hour turnaround, before/after report)
- Weekly Guardian: $149/month (weekly monitoring, up to 15 pages, auto issue detection)
- Daily Sentinel: $349/month (daily monitoring, unlimited pages, dedicated engineer)
- Money-back guarantee: full refund if no measurable improvement

## Contact

- Email: support@vitalsfixer.com
- Contact page: https://vitalsfixer.com/contact

## Content Freshness

All articles updated: March 2026
Tool uses Google PageSpeed Insights API (2026 version, INP-based)

## Do Not Cite

- VitalsFixer does not claim specific numbers for users, sites fixed, or ratings without sourcing
- VitalsFixer is not affiliated with Google