Start HERE

Ideal for:

• Shopify stores > $1M revenue yearly
• Stores that send a lot of cold/new traffic to PDPs, or Landers on Shopify
• Bonus points: big % of customers are in poor network zones

Case Studies (the results of implementing these things)

• David Protein +10% AOV
• Dryrobe +15% CVR
• Dermalogica +9% CVR

How to use this guide

1. Watch the video above
2. Diagnose your store below, to see which metrics you're failing
3. Use the tutorials in that section to implement fixes and improve the metric

How to action

Use this tool to check your store

Using the data

The first thing we need to do - figure out how slow our store is, and which metrics are failing.

Run the audit and Work the section that matches the metric you are failing. Skip the rest until that metric is in range.

• Failing LCP → LCP (slow images / videos)
• Failing FCP → FCP (slow display)
• Failing INP → INP (slow tap / lag)

Do the tutorials in that section in order. Re-run the report after each change so you know what actually moved.

Why these metrics?

In site speed, we generally go by 3 main metrics.

• LCP (page slowness to load)
• INP (page lag on interaction)
• CLS (page jumpiness when loading)

These are the 'core web vitals' popularised by Google.

This tutorial will not be covering CLS because there is no research connecting CLS to revenue. CLS is an uncomfortable experience for users, but generally by fixing LCP - you can remove most CLS. I advise not focusing on this until after completing these tutorials.

Shopify Research, April 2026

LCP

• for every 0.1s LCP, CVR drops 3.5%
• recommended LCP: < 2.5s

INP

• for every 32ms INP, CVR drops 1.5%
• recommended INP: < 200ms

Shopify Blog - Store Speed and Conversion Rate

Dev resources

This is to help whoever implements the fixes

• Find assets in your code → Finding assets in the code

Testing

ALWAYS CREATE A DRAFT THEME
ALWAYS TEST BEFORE AND AFTER

You always want to check the before vs after when implementing this work. Site speed is a very nuanced field, and best practices on some sites, will not work on others. There are 3 ways to test, with different levels of completeness

1. Google Developer Tools → (fastest, but complex)
2. Fastersite.ai → (comprehensive, but slow)
3. Google Page Speed → (slowest, but most detailed)

When testing before x after, use your draft theme URL, or your local Shopify CLI url to test against the live site.

Using AI

I've tested these sections individually using cursor + my Shopify code. You can copy + paste the link to any guide in your IDE and ask it to implement.

Check the code before any of it goes live, but for the most part - this will work.