How to Add and Customise a New Theme in Shopify (Step by Step)

Your theme controls how your whole Shopify store looks: the homepage, product pages, collections, cart and more. Changing it is one of the biggest improvements you can make, but it is also easy to do in a way that confuses customers or breaks things. This tutorial shows the safe workflow I use on client stores.

Before you start: understand "live" and "draft" themes

A Shopify store always has exactly one live (published) theme — the one customers see. You can also keep other themes in your theme library. Themes in the library can be edited and previewed without affecting the live store. That is the key idea: always build the new design in the library first, then publish when it is ready.

Step 1: Back up your current theme

1. In the Shopify admin go to Online Store → Themes.
2. Next to your current theme, open the … (actions) menu and choose Duplicate.
3. Rename the copy to something like "Backup – before redesign" with the date.

If anything goes wrong later, you can publish this backup in one click.

Step 2: Add the new theme

Option A: A free or paid theme from the Theme Store

1. On the Themes page, find the Add theme option and choose to visit the Theme Store.
2. Filter by industry, catalogue size and features you need.
3. Open a theme and use Try theme to add it to your library without publishing it. For paid themes you can usually try before buying.

Option B: Upload a theme file

If you bought a theme from a third-party marketplace, you will receive a .zip file. On the Themes page choose Add theme → Upload zip file. Only upload themes from trusted sources — a poorly coded theme can slow your store down or cause errors.

Step 3: Customise the theme

Click Customize on the new theme in your library. The theme editor lets you change content section by section.

• Theme settings (usually a brush or gear icon): colours, typography, logo, favicon, social links and cart behaviour.
• Sections: add, remove and reorder blocks such as image banners, featured collections, testimonials and newsletters.
• Page templates: use the page selector at the top to edit the product page, collection page, cart and other templates — not just the homepage.

Tip: Customise the product page template first. It is where buying decisions happen, and many store owners forget to edit it at all.

Step 4: Preview on desktop and mobile

Use the device toggle in the editor to check the mobile view — most shoppers will browse on a phone. Then use Preview to open the draft theme in a new tab and click through a real journey: homepage → collection → product → add to cart → checkout.

Step 5: Check your apps

Some apps add code or app blocks to your theme. After switching themes, confirm that reviews, upsells, chat widgets and similar apps still appear. Many modern apps use app blocks or app embeds that you enable from the theme editor.

Step 6: Publish

When everything looks right, go back to Online Store → Themes, open the actions menu on the new theme and choose Publish. Your old theme moves to the library, so you can switch back if needed.

Common mistakes to avoid

• Editing the live theme directly during a big redesign.
• Forgetting to update navigation menus (they are managed under Online Store → Navigation, not inside the theme).
• Uploading huge, uncompressed images that slow the store down.
• Installing several themes' worth of apps and never removing the old ones.

Next, make sure your product pages are ready to convert with our guide to optimising Shopify product pages.

How to choose the right theme

Before falling in love with a demo, check three things. First, catalogue size: some themes are designed for a few hero products, others for hundreds of items with filters. Second, the features you need out of the box, such as mega menus, product filtering, colour swatches or quick view. Third, speed: open the theme demo on your phone using mobile data and see how quickly it becomes usable.

Also read the theme's documentation and support policy. A well-supported theme receives updates when Shopify introduces new features, which saves you money on developers later.