How to Speed Up Your Shopify Store: A Practical Guide

The average Shopify store scores 56 out of 100 on PageSpeed mobile. That is not a rounding error — it is a conversion problem sitting in plain sight. A one-second improvement in load time can increase conversions by up to 7%. For a store turning over £500k a year, that is £35,000 in additional revenue from a technical fix.

Here is how to find what is slowing your store down and fix it.

Start With a Proper Audit

Before making any changes, run your store through Google PageSpeed Insights and note the specific diagnostics. The score itself matters less than the individual issues flagged. Focus on:

• Largest Contentful Paint (LCP): how long before the main content loads
• Cumulative Layout Shift (CLS): how much the page jumps as it loads
• Interaction to Next Paint (INP): how quickly the page responds to input

Also run your store through CommerceRank.ai to see how your scores compare against similar stores in your category.

Fix Your Images First

Images are the single biggest contributor to slow Shopify stores. Most merchants upload images at full resolution from a camera or design tool, then rely on Shopify to resize them. Shopify does resize images automatically, but it cannot fix format or compression issues at source.

What to do:

• Convert product images to WebP format before uploading
• Keep hero and banner images under 200KB
• Use Shopify's image_url filter with explicit size parameters in your theme code rather than loading full-resolution images everywhere

For existing images already in your media library, a bulk optimisation app can reprocess them without requiring a re-upload.

Audit Your Apps

Every app that injects JavaScript or CSS into your storefront adds weight. Some apps add 50 to 100KB of script per page load even when the feature they provide is not visible or relevant on that page.

Go to your Shopify admin, open the Theme Editor, and check the App Embeds section. Disable any app embed you do not actively need on every page. For apps that must load scripts, check whether they offer options to load only on relevant pages (for example, a chat widget loading only on product and cart pages rather than every page).

Our data shows stores that have audited and trimmed their app stack improve PageSpeed scores by an average of 8 to 12 points.

Choose a Faster Theme

If your store is running a heavily featured premium theme with scores in the low 40s, no amount of optimisation will fully compensate for the baseline weight of the theme itself. The fastest themes in our dataset are Craft (67), Sense (66), Refresh (63), and Dawn (60).

Switching themes is disruptive, but if your current theme is consistently pulling scores below 45 and you have already addressed images and apps, the theme is the limiting factor.

Reduce Render-Blocking Scripts

Render-blocking scripts are resources that must load before the browser can display the page. Common culprits are Google Tag Manager containers with too many tags, third-party chat widgets, and analytics scripts loaded synchronously.

In your theme code, move non-critical scripts to load with the defer or async attribute. If you are using Google Tag Manager, audit your container and remove tags that are firing unnecessarily on every page view.

Use Shopify's Built-in CDN Properly

Shopify serves assets through Fastly's global CDN, which is one of the fastest available. You get this automatically, but you can take better advantage of it by ensuring your theme references assets via Shopify's asset pipeline rather than loading them from external hosts.

External font libraries like Google Fonts add an additional DNS lookup. Self-host your fonts via your Shopify theme instead.

Set a Baseline and Monitor

Speed is not a one-time fix — it degrades as you add apps, upload new images, and run promotions that add scripts to your pages. Set a monthly reminder to run a PageSpeed audit and compare against your baseline.

Stores that monitor performance consistently maintain scores 15 to 20 points higher than stores that only check after something breaks.