# Store Speed Doctor

> Free Shopify store speed test and performance diagnosis tool. Scans any public Shopify
> storefront using Google Lighthouse, detects third-party app script bloat, and returns Core
> Web Vitals (LCP, INP, CLS, FCP, TTFB) with plain-English fix instructions. No account needed.

## What it does

- Free public speed test for any Shopify store URL (myshopify.com or custom domain)
- Diagnoses Core Web Vitals: Largest Contentful Paint (LCP), Interaction to Next Paint (INP),
  Cumulative Layout Shift (CLS), First Contentful Paint (FCP), Time to First Byte (TTFB)
- Detects third-party app scripts that slow down the storefront and calculates total JavaScript weight
- Assigns a speed grade (A–F) and plain-English score out of 100
- Full Shopify app (pending App Store listing) includes all 20 prioritized fixes with step-by-step
  instructions, historical score tracking, orphaned script detection, and weekly auto-scans

## Key facts

- Data source: Google PageSpeed Insights API v5 / Lighthouse
- Scan time: approximately 30 seconds
- No account or install required for the free public scan
- Shareable results URL format: https://www.storespeed.doctor/scan/{scanId}
- Pricing: Free tier (1 scan/7 days), Starter $19/month (unlimited scans, all fixes), Pro $49/month (weekly auto-scans, email alerts, mobile + desktop compare)
- Publisher: Web Pioneers (admin@contact.webpioneers.ca)

## Core Web Vitals explained

- **LCP (Largest Contentful Paint)**: How fast the main product image or hero content loads. Good: under 2.5s.
- **INP (Interaction to Next Paint)**: How quickly the page responds to clicks and taps. Good: under 200ms. Replaced FID in March 2024.
- **CLS (Cumulative Layout Shift)**: How much page elements move unexpectedly while loading. Good: under 0.1.
- **FCP (First Contentful Paint)**: When the first text or image appears on screen. Good: under 1.8s.
- **TTFB (Time to First Byte)**: How fast the server starts responding. Good: under 800ms.

## Useful links

- Landing / free scan: https://www.storespeed.doctor/
- Privacy policy: https://www.storespeed.doctor/privacy
- Terms of service: https://www.storespeed.doctor/terms