How to audit your Shopify speed without getting lost

Most Shopify store owners I talk to have a vague feeling that their store is "slow," but no clear way to tell if that matters. This post is the short version of the audit I run on every Sprint client, written so you can do the first pass yourself.

Start with the metrics that matter

Forget PageSpeed Insights scores. They're too coarse to act on. Instead, look at these three things:

1. Largest Contentful Paint (LCP) on mobile. This is how long it takes for the biggest thing on your page to show up. Under 2.5 seconds is good.
2. Cumulative Layout Shift (CLS). This measures how much your page jumps around while it loads. Under 0.1 is good.
3. Time to First Byte (TTFB). How long your server takes to start responding. Under 0.8 seconds is good.

You can pull all three from web.dev's measure tool or Chrome DevTools. Run them on your product page, not your homepage. That's where most of your conversions happen.

Check your actual users, not just tests

Synthetic tests tell you one thing, real users tell you another. Open your Shopify admin, go to Online Store, then Preferences, and turn on Google Analytics if you haven't already. Wait a week. Then look at page load time by device. If 70% of your traffic is mobile and your mobile load time is over 4 seconds, that's where your money is leaking.

The short list of usual suspects

When I start a speed audit, these are the first things I look at:

• App count. Every app adds JavaScript. I've seen stores with 40+ apps installed. That's 40+ scripts competing for your users' phones.
• Image sizes. Shopify will serve whatever you upload. If you uploaded a 4 MB hero image, your visitors download a 4 MB hero image.
• Third-party pixels. Facebook, TikTok, Google Ads, Klaviyo. Each one is another script that has to load before your page becomes interactive.
• Theme code quality. Old themes accumulate dead code. Snippets that referenced removed sections. Loops that iterate over everything in your store. CSS files that nothing uses anymore.

None of this is glamorous. Fixing it isn't either. But it's almost always worth more than chasing the next design trend.

When to call in help

If you ran the audit and you know what's broken, fix it. If you ran the audit and the list is overwhelming, or you're not sure which fixes are safe, that's what a Sprint is for. One fixed price, one clean store, no ongoing decisions to make.