How to improve your Shopify storefront

We measure Shopify stores every week. The same faults come up again and again. Here is the whole list, in the order worth doing.

Every check takes minutes. Do them on a phone-size screen with an empty cache, because that is how a first-time shopper arrives.

The numbers to beat

Before you start

Open your store in Chrome. Then:

• Press F12 to open the developer tools.
• Click the small phone icon to switch to a phone-size screen.
• Open the Network tab. Tick "Disable cache".
• Reload the page.

You now see your store the way a new shopper does. Keep this window open for every check below.

1. Speed

How long the main image takes

Check: run your home page through Google PageSpeed Insights. Read the number called Largest Contentful Paint.

Aim for: under 2.5 seconds.

Fix, in this order:

• Find the biggest image on the first screen. Make sure it is not a video.
• Give that image a width and a height in the code.
• Remove "lazy loading" from that one image. It is the image everybody sees.
• Add lazy loading to every image below it.
• Load your brand font with swap, so text draws at once in a normal font.

How much a first visit downloads

Check: in the Network tab, reload and read the transferred total at the bottom.

Aim for: under 2 MB. Under 1 MB feels instant.

Fix:

• Sort the Network list by size. The top five rows are your problem.
• If a photo is over 200 KB, it is too big. Export it again at the size it is shown.
• Use Shopify's image sizing so a phone gets a phone-size photo.
• If your home page autoplays a video, show a still image first. Load the video after.

2. The page moving while people read

Check: PageSpeed Insights again. Read Cumulative Layout Shift.

Aim for: under 0.1. Zero means nothing moves.

This is the jump that makes a shopper tap the wrong thing. Google counts it against you in search.

Fix:

• Give every image a width and a height. This one change fixes most stores.
• Give your discount bar and cookie notice a fixed height, or lay them over the page.
• Keep a space the right size for review stars and size guides that load late.
• Pick a fallback font close in size to your brand font.

3. Apps and scripts

Check: in the developer tools, open the Console. Typedocument.scripts.length and press Enter.

Aim for: as few as you can. The nine stores we measured ran 113 on average, and 85 of those belonged to other companies.

Fix:

• Open your app list. For each app, ask what breaks tomorrow if it is gone.
• If nothing breaks, uninstall it.
• Uninstalling is not enough. Search your theme for leftover code from apps you removed.
• Hold chat, pop-ups and review widgets until the shopper scrolls or taps.

We published the code for that last one:delay third-party scripts until first interaction.

4. Errors nobody sees

Check: open the Console tab and reload. Count the red lines.

Aim for: zero.

One store we measured logged 93 on a single visit. Errors are how a size picker or an add-to-cart button stops working for some shoppers, while everything looks fine in the office.

Fix:

• Check the product page as well as the home page. They break differently.
• Ignore blocked tracking pixels. They are noise.
• Fix anything that names one of your own files.
• Report the rest to the app maker. Remove the app if they will not fix it.

5. Shoppers who cannot see the screen

Some people shop with a screen reader, which reads the page aloud. EU rules have applied to online shops since June 2025, and the UK has its own duty.

Images

Check: in the Console, type this and press Enter:

document.querySelectorAll('img:not([alt]), img[alt=""]').length

Aim for: zero.

Fix: write a description for every image that shows a product. Say what it is, not "product photo". Leave the description empty only for a background pattern.

Buttons

Check: press Tab over and over from the top of the page. Watch where the outline goes.

Aim for: you can reach the cart, the menu and the search box, and you can always see where you are.

One store we measured had 414 buttons and links with no name. A screen reader announces those as "button" and nothing else.

Fix:

• Give every icon button a name in the theme. One line each.
• Name colour swatches by colour, not by position.
• Never remove the focus outline. Restyle it if you dislike it.
• Make sure text colour stands out against its background.

6. What Google and AI assistants read

Every product page carries a hidden block of data. Google builds your search result from it. AI shopping assistants read the same block.

Check: run a product page through Google's Rich Results Test.

Aim for: name, price, stock status, rating, brand and an image, all present.

Five of the six big stores we checked send no rating at all. Their reviews sit on the page where shoppers see them, and never reach Google.

Fix:

• Pass the rating and review count from your reviews app into that block.
• Add the stock status. Without it, Google sends shoppers to sold-out products.
• Give your home page a description and a share image.
• Check that your sitemap lists your products.

More on this:your reviews may never reach Google.

7. Measure again

Write today's numbers down before you change anything. Measure again after each change.

Scores move in steps, and you want to know which step each change bought. Stores also get slower on their own. We measured one store twice, six days apart, and it had gained 15 MB in between. Nobody there knew.

Put a reminder in the calendar for one month from now. Run the whole list again.

If you would rather not

Send us your store address. We measure it, and send you the list with your numbers in it. Free, and we will tell you honestly if your store is already fine.