Theme updates bring bug fixes, performance work and support for new Shopify features. They are also the moment many stores lose months of small code changes, because the update process only carries over part of what you changed. Here is what survives and how to update safely.
What carries over and what does not
| Change | Survives the update? | Why |
|---|---|---|
| Theme editor settings (colours, fonts, sections, blocks) | Yes | Stored in the theme's settings and JSON templates, which Shopify migrates |
| Templates created in the editor | Usually | JSON templates move across; check any custom template assignments |
| Edits to existing code files | No | The update replaces the theme's own files with the new version |
| New sections and snippets you added | No, unless copied | They are not part of the new version and need to be added again |
| App blocks and app embeds | Yes | Apps that use theme app extensions sit outside the theme code |
| Code an old app pasted into the theme | No | Often a good moment to find out whether it is still needed |
A safe update routine
- Keep the live theme in Git through Shopify's GitHub integration or Shopify CLI, so every code change is on record.
- Before updating, list the code changes since the last version: a diff between your theme and the clean version it is based on.
- Add the update. Shopify creates an unpublished copy with the new version and your editor settings.
- Reapply the code changes on the copy. Where the new version already solves a problem you patched, drop the patch.
- Test the copy in preview: product pages, variants, cart, search, filters, app blocks, tracking and every language.
- Publish at a quiet hour and keep the previous theme in the library for a quick rollback.
Make the next update easier
The less you edit the theme's own files, the cheaper each update becomes. Put custom work in new sections and snippets with your own prefix, use metafields instead of hard-coded content, and prefer apps that use app blocks over apps that inject code. Note every unavoidable edit to a core file in a short changelog.
How often to update
You do not need every release. Check the changelog once a quarter and update when a version fixes something you use, improves performance or adds a feature you want. A store that has skipped many versions is better updated in one planned project than in a rushed afternoon.
When the update button is not there
Themes not bought from the Theme Store, heavily rebuilt themes and themes that were duplicated and renamed often cannot use the one-click update. Then the update is a manual merge of two code bases, or the moment to ask whether a custom theme would be cheaper over time — see custom theme vs premium theme.
We do theme updates as part of Shopify theme development and in our support plans. To see which theme and version a store runs, use the theme finder.