The single safest habit in Shopify is to work on a duplicate theme rather than your live one. By the end of this you will have a workflow that lets you change anything, check it properly, and publish only when you are satisfied. This matters more than usual with Atlas, because switching themes can silently disable Atlas features.
In this article:
Step 1: Duplicate your theme
In your Shopify admin, go to Online Store, then Themes.
On your live theme, select the three-dot menu, then Duplicate.
Rename the copy something meaningful, such as the date and what you are changing.
The duplicate sits in your theme library, unpublished and invisible to customers.
💡 Rename duplicates as you create them. A theme library full of entries called "Copy of Copy of Dawn" is how the wrong theme gets published.
Step 2: Make your changes on the copy
Select Customize on the duplicate and work there. Nothing you do affects your live store.
Step 3: Set up Atlas on the copy
⚠️ Do this before publishing, not after. Atlas extensions are enabled per theme, and a duplicate does not reliably carry them. Publishing a theme without them disables every Atlas feature at once, with no error anywhere.
On the duplicate:
Open Theme settings, then App embeds, and turn on
Atlas Page BuilderandAtlas Cart Upsells. Save.Add the
Atlas Bundlerblock to your product template or templates. Save.In Atlas, use
Publish againon each page you want on the new theme, selecting the duplicate.
Step 4: Preview properly
From Online Store, then Themes, select the three-dot menu on the duplicate and choose Preview.
Check, at minimum:
Check | Why |
A product page with a bundle | Confirms the Bundler block is placed correctly |
An Atlas-generated page | Confirms the Page Builder embed is on |
The cart drawer, with something in the cart | Confirms the Cart Upsells embed is on |
Checkout, with a bundle in the cart | Confirms discounts still apply |
The whole thing on a phone | Most of your traffic |
The preview link can be shared, which is useful if someone else is reviewing.
Step 5: Publish
When you are satisfied: Online Store, then Themes, then Publish on the duplicate.
ℹ️ Publishing swaps the whole theme, not individual changes. Anything altered on your live theme since you duplicated it is not in the copy. If that gap is more than a few days, consider making a fresh duplicate and reapplying your changes.
Step 6: Check Atlas afterwards
Open your Atlas dashboard and look at the Theme extensions card. All three should show Active or Added, on the newly published theme.
Then check your storefront: a product page with a bundle, and the cart drawer.
Going back
Your previous theme stays in your theme library. To revert, publish it again.
⚠️ Reverting also reverts anything else that changed in the meantime, including Atlas pages published to the newer theme. Reverting is a rollback of the whole theme, not an undo of one change.
Shopify keeps some version history per theme, under the theme's three-dot menu. Find it before you need it.