The Shopify Performance Checklist for 2026

Slow stores lose money. A 1-second improvement in Largest Contentful Paint correlates with a 7% lift in conversion across the Shopify Plus stores we’ve audited this year.

Here’s the prioritized checklist we run on every audit.

1. Audit your theme — first

Before installing apps or rewriting code, run a clean audit on your current theme:

# Use Lighthouse in CI
npx lighthouse https://yourstore.com --only-categories=performance --form-factor=mobile

If you’re using a 2020-era theme, upgrading to a modern Online Store 2.0 theme (Dawn, Sense, or a Hydrogen build) often delivers a 30%+ LCP improvement on its own.

2. Lazy-load below-the-fold images

In Liquid:

{{ product.featured_image | image_url: width: 800 | image_tag: loading: 'lazy', sizes: '100vw' }}

For the hero image, use loading="eager" and fetchpriority="high".

3. Audit your apps

Open your store with the Shopify Theme Inspector. Every app injects scripts. Common culprits:

• Review widgets that load 200KB of JS for a single star rating
• Personalization apps that block first paint
• Pop-up apps that render before content

Rule of thumb: if an app adds more than 30KB to your homepage, it needs to justify itself in conversion lift.

4. Use the Shopify CDN aggressively

Always use image_url with explicit width parameters. This enables WebP/AVIF auto-conversion and width-appropriate variants.

5. Move to checkout extensions

If you’re on Shopify Plus and still using checkout.liquid customizations, migrate to checkout extensions before the August 2026 deadline. Beyond compliance, extensions are faster and don’t block checkout rendering.

---

Want the full step-by-step? See the 60-minute Shopify performance audit in Merchant Solutions.