Update your Shopify theme in a draft, then check the customizations your store depends on before publishing it. A successful update message is the start of that check, not proof that every feature still works.
This walkthrough is for merchants updating the same theme to a newer version. Moving to a different theme is a separate rebuild: don't assume its settings, sections or app placements will match.
Identify the update and keep a recovery copy
In Online Store, open your theme's version details and read the release notes. Write down the current version, proposed version and the change you need. That might be a specific bug fix or a feature your team will actually use.
Use the theme's actions menu to duplicate the current version before changing it [2]. Give the copy a date and a clear name, such as ‘Before September update’. Keep a separate record of app settings or other store changes involved; a theme copy isn't a whole-store backup.
Ask whoever last customized the store for a list of code edits. If they don't have one, allow time to inspect the changes. Guessing from the homepage misses work on product templates, search, the cart and less-used pages.
Make a short list of customizations to check
List the behavior you need to preserve, where it appears, how it was added and who can repair it. Include one real URL and an expected result for each item. ‘Product page looks right’ is too broad; ‘delivery note appears on the large-item template’ gives someone a useful test.
| Customization | Where to investigate | What to verify in the draft |
|---|---|---|
| Announcement text or section order | Theme editor settings | Correct content, order and links |
| Custom styling | Custom CSS or a stylesheet file | The rule still affects its intended element |
| Extra product logic | Liquid or JavaScript code edits | The feature works through the affected customer steps |
| Chat, reviews or another widget | App block, app embed or injected code | Correct placement, activation and behavior |
This is a suggested worklist, not an exhaustive Shopify compatibility test. Choose examples from your store, including a product with unusual options and any template that receives paid traffic. Keep a screenshot of the old behavior, but write down the result as well.
Add the update to draft themes
For a supported Theme Store update, open the update notification and choose Add to draft themes. The current published theme stays in place while you review the new copy [1].
Shopify says theme-editor customizations carry into this update. Code edits made manually or by an app carry over when they don't conflict. Read the resulting theme-card message to see whether code edits were included. If they weren't, preserve the old code and ask your developer to reapply the needed changes to the updated version [1].
Don't paste entire old files over the new theme just to restore a feature. That can replace the very update you wanted. Give the developer the affected files and the expected behavior so they can compare and adapt the specific changes.
If the standard update option is missing, Shopify describes a fresh-install route with manual customization. Themes bought outside the Theme Store need their designer's update instructions [1]. Stop and establish which route applies before following a tutorial for another theme.
Test the effect, not just the copied setting
A customization can still exist in the editor and fail on the page. Shopify specifically warns that custom CSS can stop working when the theme's selectors or classes change [3]. A selector is the part of a CSS rule that identifies the page element to style.
For an illustrative example, an old rule targets .delivery-note. The updated page uses .delivery-message instead. The rule is still present, but it no longer matches that element. A developer should inspect the new page structure and intended scope before choosing a replacement selector; these example names aren't Shopify's actual theme classes.
For apps, identify how each one reaches the page. A block lives in a supported section or template; an embed can supply an overlay or background code; another app may have edited theme files directly. Shopify documents these different integration routes [4]. An installed app alone doesn't establish that its storefront feature works in your draft.
Check app placements and embed settings in the updated theme, then test the feature in its preview. Shopify's same-theme update guidance describes copying app-extension settings, while its general theme-switching guidance warns that apps may need reactivation [1,4]. Treat activation and behavior as checks in both cases, especially when starting from a fresh copy.
Work through your list on desktop and a narrow phone screen. Open a menu, use search, choose the affected product options, add an item and inspect the cart. If the update touches a subscription, bundle or other specialist feature, include that journey. Record the exact product, device and market used so another person can reproduce a failure.
Publish the reviewed version and check the live store
Agree who will publish, who will check the live journeys and who can restore the previous theme. Resolve required failures first. If a change is intentionally retired, record that decision instead of marking a missing feature as passed.
When you publish the reviewed draft, Shopify moves the previous published theme into Draft themes [5]. Keep it available. Verify the live store from its ordinary public URL, without the draft preview, and repeat the important customer steps. Theme publication doesn't reverse separate app or admin changes; use the release guide below if the update includes them.
Questions before you update
Do I need a developer for every theme update?
Will a theme backup include my products and orders?
Can I keep editing the live theme while someone checks the update?
Start with the last customization your team paid to add. Find its owner and write a test that proves it still works in the updated draft. That one specific check is more useful than approving an update from its version number.
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