App integrations, styling changes, theme enhancements—there are many reasons to modify the theme files. However, theme file customizations are a common obstacle for merchants when updating to the latest version. This article presents some strategies and best practices for preparing, migrating, and restoring custom theme file modifications in an updated theme version.
Preparing for the update
There are a few steps we recommend you complete before beginning the manual update to your modified theme.
Duplicate your current theme
First, select [···] > Duplicate to create a backup of your theme. This will serve as a backup reference in case any changes are lost.
Check which apps are in use
Apps often need to connect with the store's theme through modifications to the theme files. This can be automatic, manual, or a task the app's development team performs. It is important to look at which apps are being used to determine if integration with the new theme will be automatic or require action.
Identify which files have been modified
In the current theme, go to Actions > Edit code to access the theme files. In this view, there should be small circles to the left of the theme file names if modifications have been made.
Another sign that a theme file is modified can be found when opening a particular theme file. If we open the theme.liquid, for instance, there will be a link at the top labeled Older versions. This can be used to revert the theme file back to its previous state. This feature only appears for certain files.
Take note of the modified file names as these will likely need to be adjusted in the new version.
Migrating modified content
There are a few routes for updating a modified theme.
Use Theme Updater
Theme Updater can carry over content and settings from a previous (compatible) version. Select Preserve customizations when using the app to migrate as many modifications as possible to the new version.
Which theme versions are compatible with Theme Updater?
Should I use Theme Updater to migrate my vintage theme?
What do the red and green code comparisons mean?
Another route is to update manually. This is achieved by adding the latest version to your Online Store and copy-and-pasting the custom content from one theme editor (original theme) to another (new theme).
For more information on these approaches, explore how to update your Shopify theme manually.
Get hands-on help
Another route for updating modified themes is to let Storetasker do the heavy lifting.