Your Shopify store is slow: what it costs and how to fix it

Your store looks fine on your laptop at home. On a customer’s phone, on mobile data, the first screen takes long enough that some of them are gone before the product appears. Shopify store speed is one of the few problems you can measure for free, and many of the fixes are in your admin.

Why slow pages lose sales

A visitor who arrives from an ad or a search result has not decided to buy. They are deciding whether to look. A blank or half-loaded screen is the easiest moment to go back, and you have already paid for that visit in ad money or in effort.

Speed matters again later. When a tap on a size option or the add-to-cart button lags, the store feels unreliable at the moment you are asking for a card number. And when the page jumps as it loads, people tap the wrong thing.

Slow pages are one of several leaks, and we list the others in why visitors leave without buying. This one is worth fixing early because it sits in front of all the rest.

Measure your Shopify store speed first

Open PageSpeed Insights, Google’s free test, paste in the address of your best-selling product page and run it. Read the mobile result first.

The report has two parts. The top shows what real visitors experienced, if your store has enough traffic for Google to have collected it. The lower part is a test run right now on a simulated phone, with a list of what is slowing the page down. A small store often sees only the lower part, and that is enough to work with.

Test three pages: the home page, one collection and one product. Run each test more than once, because results vary a little from run to run, and write the numbers down before you change anything.

Measure before you change anything and again after each fix. Otherwise you are guessing.

The three Core Web Vitals in plain words

The report is built around three measurements that Google calls Core Web Vitals. The thresholds below are the ones Google publishes as good in its guide to Web Vitals.

The last one is a score, not a time. In our experience the first one is where small stores most often fall short, and it is mostly about images. Do not chase a perfect overall score. Get these three into the good range on your main pages and move on.

The fixes, in order of payoff

1. Images. This is usually the biggest win. Shopify already helps: it serves your images from its own network, in newer formats where the browser supports them. It cannot fix a photo uploaded straight from a camera at many times the size it is shown, or a first screen that loads several large images at once. Resize photos before you upload them, use JPEG for photographs and keep PNG for graphics that need a transparent background, and put one image on the first screen, not several.

2. Apps and their scripts. An app that shows something in your storefront usually adds its own code to your pages, sometimes to every page. Open Settings, then Apps and sales channels, and remove every app you no longer use. Then open the theme editor, click App embeds in the sidebar, and switch off the ones you do not need. This also trims your monthly bill.

3. Heavy themes and sliders. A theme with every feature switched on loads the code for all of them. The usual culprit is the slideshow at the top of the home page: several large images and a script, on the screen that matters most. Replace it with one image and one headline, and delete home page sections nobody scrolls to. If the theme itself is the weight, our guide to custom design or a ready theme will help you decide what to do about it.

4. Fonts. Every font family, and every weight of it, is a file a phone has to download before your text looks right. Keep to one or two families and the weights you really use. In the theme editor, open Theme settings, then Typography. System fonts in that list are already on the visitor’s device and cost nothing to load.

5. Video. A video that plays by itself on the first screen is among the heaviest things you can put there. If it earns its place, keep it short and muted, show a still image until it is ready, or move it further down the page. An embedded player from a video site brings that site’s scripts with it, so let it load only when someone presses play.

What you can do yourself, and what needs a developer

Before you change anything, make a copy of your theme: go to Online Store, then Themes, open the three-dot menu and choose Duplicate. Work on the copy, check it, then publish it.

In the admin, yourself: resize and replace images, remove unused apps, switch off app embeds, swap the slider for a single image, cut fonts, delete sections and move video down the page. In our experience that covers the larger part of the gain for a small store.

With a developer: cleaning out code that removed apps left behind in the theme, changing how the theme loads images and scripts, and replacing a heavy feature with lighter code. These touch the theme’s files, where a small mistake can break the page.

If you would rather start from a store that is fast by design, fast pages are included in the Ecommerce Scaling System, our custom Shopify store built for you. And if search traffic matters to you, pair this article with our Shopify SEO checklist.

What to do first, today

Run your best-selling product page through PageSpeed Insights on mobile and write down the three numbers from the table. That is your starting line.

Then do two small jobs: replace the largest image on your first screen with a properly sized one, and remove one app you no longer use. Test again and compare.

Shopify store speed is not a job you finish once. Every new app, banner and video adds weight, so repeat the test whenever you add something, and keep the store as light as the day it passed.