How to speed up your Shopify store: what really moves Core Web Vitals

Nico Bértolo · 2026-08-21

In short

  • Google measures speed with three metrics: LCP (loading), INP (responsiveness) and CLS (stability).
  • On Shopify, what slows things down is usually apps and third-party scripts, not Shopify itself.
  • Always measure on mobile: it’s where most of your traffic is and where it shows most.

A slow store loses customers before they see the product, and it also ranks worse. The good news is that Shopify’s foundation is fast: slowness almost always comes from what has been added on top.

The three metrics Google looks at

  • LCP · loading: How long the main element takes to appear. Target: 2.5 seconds or less.
  • INP · responsiveness: How long the page takes to react when you tap something. Target: 200 ms or less.
  • CLS · stability: How much content shifts while loading. Target: 0.1 or less.

What usually slows down a Shopify store

  • Installed (and uninstalled) apps that keep loading code.
  • Third-party scripts: chats, pixels, pop-ups and review widgets.
  • Huge images uploaded without optimisation.
  • Themes overloaded with effects and unused sections.
  • Videos that load even when the customer never sees them.

What to fix first

  1. Audit your apps: Remove the ones that add nothing and check uninstalled ones haven’t left code in the theme.
  2. Control third-party scripts: Load only what’s essential and defer what isn’t needed at first.
  3. Optimise the main image: The first image the customer sees decides LCP: the right size and a modern format.
  4. Reserve space for late-loading elements: Banners and widgets with reserved space stop the page from “jumping”.

Measure with PageSpeed Insights on mobile before and after every change. Without a baseline, you won’t know what worked.

Frequently asked questions

Is Shopify slow?

Not by itself. The platform is fast; what usually slows it down is apps, external scripts and unoptimised images.

Does speed affect SEO?

Yes. Core Web Vitals are among the factors Google considers, and a slow store also converts worse.

Does changing theme speed up the store?

It can help if the current theme is overloaded, but review apps and scripts first, as they’re usually the main cause.