How to update your Shopify theme without losing customizations

To update a Shopify theme without losing customizations, click Add to draft themes on the update notice, let Shopify build an "Updated copy of" your theme, and check what came across before you publish. Theme editor work (settings, sections, blocks, templates, wording) carries over automatically. Code edits carry over only when they don't conflict with the new version, so back up the theme, diff your custom code, re-apply anything Shopify couldn't include, test, and only then publish.

Most "my theme update wiped my changes" stories come from one of two things. Either the custom code conflicted with the update and nobody checked the message Shopify showed, or someone published the updated copy straight away. Both are avoidable. The update never touches your live theme until you click Publish.

How do Shopify theme updates work?

Shopify installs the new version next to your current theme as a draft, and your live store keeps running the old version until you publish. You find updates in your Shopify admin under Online Store, where the theme's version number turns into an update notification when a new version exists.

The flow, per Shopify's help page on updating themes:

1. Go to Online Store and click the version number on your theme.
2. If an update is available, click the notification to open the details. You can click View release notes first.
3. Click Add to draft themes. Shopify adds the new version as a draft named "Updated copy of" your theme.
4. Click Review to check it, then Publish when you're ready.

Shopify says the update can take several minutes depending on the size of the theme. Adding the draft doesn't change your current theme or any other theme in your library.

Two limits catch people out. Only themes installed from the Shopify Theme Store get updates. If you uploaded a zip file, bought the theme from a designer outside the Theme Store, or are still on a vintage theme, there is no update button. And each update adds a theme to your library, which holds up to 20 themes on Basic, Grow and Advanced and up to 100 on Plus. Old "Copy of" duplicates fill that up faster than you'd think.

What carries over when you update a Shopify theme?

Everything you did in the theme editor carries over, and code edits carry over only when they don't conflict with the new version. That split is the whole game.

After the draft is added, Shopify shows one of two messages: "Theme added: code edits successfully included" or "Theme added: code edits could not be included". Read it. The second one means your code changes are not in the updated copy. Shopify's code editor page is blunt about this: if your code changes conflict with a theme update, all your code changes are removed in the updated copy.

There's one more way an update can fail. Shopify notes that changes to a section's schema limits, such as raising a block limit or loosening where a section can be placed, might cause the update to fail. If a developer edited section schemas on your store, expect trouble here.

Separately, Shopify may apply automated updates. Shopify describes these as bug or security fixes that aren't meant to change your look, content or settings. Feature updates are the ones you add yourself.

What should you check before updating?

Spend twenty minutes on this list before you click anything. It's what I run on every client store before an update.

1. Know your current and target versions. Click the version number and read the release notes for every version in between, not just the latest.
2. Look for breaking changes. Release notes flag them. Dawn 16.0.0, released in August 2026, removed the legacy customer account templates and said stores on legacy customer accounts must upgrade before publishing that version. Miss that line and your login pages break.
3. Duplicate the live theme. Shopify recommends this before any code work. It's your rollback point.
4. Save a copy of your custom code. Use Download theme file in the theme's actions menu on the Online Store page (Shopify emails you a zip) or pull it with Shopify CLI. The code editor's Timeline restores one file at a time, has finite history, and doesn't cover files in the assets folder, so don't treat it as a backup.
5. List every app that touches the theme. Note which use app blocks or app embeds and which pasted code into theme files.
6. Free up library space. Delete stale drafts if you're close to the 20-theme limit.
7. Pick a quiet window. Not the week of a sale, a launch or a big ad push.

How do you update a Shopify theme step by step?

Here's the full process I follow, from backup to publish. On a lightly edited theme it takes a few hours with testing. On a heavily edited one, most of the time goes into steps 4 and 5.

1. Duplicate your live theme and rename the copy with the date, for example "Backup before 16.1 update, Oct 2026".
2. Add the update with Add to draft themes. Note which message Shopify shows about code edits.
3. Find your custom code. Pull your live theme and a fresh, unedited copy of the same version you're on, then diff them. With Shopify CLI, shopify theme pull --theme followed by the theme ID or name downloads any theme in your library. Any diff tool works. If your theme is connected through Shopify's GitHub integration, the commit history already shows every change, and the integration also commits edits made in the theme editor and code editor back to the branch.
4. Re-apply what didn't carry over. Go through the diff file by file. For each change, decide if it's still needed (new versions often add features you previously coded by hand), then port it into the updated copy. Re-test any custom CSS, since class names change between versions.
5. Test the updated copy before publishing. Use Preview and share the preview link with your team. Shopify's visitor preview links expire after 2 days, so make a new one if testing runs longer. Check the list below.
6. Publish in a low-traffic hour. The old theme stays in your library as a draft, so rolling back is one click.
7. Watch for a week. Check conversion rate, add-to-cart rate and any app support tickets against the previous week.

My test list for step 5, on a real phone on mobile data and on desktop:

• Home, collection, product, cart, search and 404 pages
• Variant picker, sold-out states, product badges and metafield content
• Cart drawer, cart page, discount codes and checkout handoff
• Every app: reviews, subscriptions, wishlist, WhatsApp, upsells, tracking pixels
• Customer login and account pages
• Translations and currency selector if you sell in more than one market
• Speed: run PageSpeed Insights on the preview and compare with the live theme

If the update touches anything you sell on, like the product form or cart, place a real test order. If you need a hand with this, send me your store details and I'll tell you how big the job is.

How do you structure custom code so future updates are easy?

Keep your customizations out of the theme's own files. Shopify carries over editor work automatically and only fails on code that conflicts, so the less you edit core files, the smoother every future update gets.

The order I work in on every build:

A few practical rules come out of that table:

• Prefer apps built on theme app extensions. Shopify's developer docs say these apps don't edit theme code, which lowers the risk of breaking changes. When you uninstall an old app that injected code into your theme, clean the leftovers out too.
• Create, don't edit. If you need a custom product section, copy the theme's main product section into a new file with a new name and change that. Shopify's update sees a file it doesn't own and leaves it alone.
• Use Custom Liquid for one-offs. Dawn, for example, ships a Custom Liquid section. Paste a tracking snippet or a small HTML block there rather than editing a template file.
• Keep CSS in your own file. One custom stylesheet loaded after the theme's CSS is far easier to re-check than edits spread through the theme's own stylesheets.
• Write down every core-file edit. A short changelog in the repo or a shared doc saves hours at the next update.

Shopify's newer Horizon themes are built around theme blocks, and AI-generated blocks land in the blocks folder as self-contained files. Shopify says that's so you can still update the theme when new versions ship.

When should you not update your Shopify theme?

Don't update in the middle of a sale or launch, and don't update a theme so heavily edited that the update is really a rebuild. In those cases, wait or plan it as a proper project.

Hold off when:

• You're inside a sale, launch or big campaign. Update a week before or after.
• The release notes have a breaking change you aren't ready for, like Dawn 16.0.0's removal of legacy customer accounts.
• Shopify couldn't include your code edits and the diff runs to dozens of files. At that point you're rebuilding customizations on new code. Scope it, quote it and schedule it.
• Your theme isn't from the Theme Store. There's no update to apply. Talk to the theme's developer, or plan a move.
• You're on a vintage theme. Shopify no longer updates vintage themes. Your options are moving to a newer theme or having a Partner upgrade it.
• A key app hasn't confirmed support for the new version. Check with the developer first.

Skipping updates forever is also a choice with a cost. Every version you skip makes the next jump bigger, and new Shopify features (customer accounts, product disclosures, AI blocks) arrive through theme versions. I'd update once or twice a year, or roll it into a maintenance retainer so it happens without anyone having to remember.

What do you do if an update already wiped your changes?

Don't panic, because the old version is almost certainly still in your library. When you publish an updated copy, the previous theme moves to your draft themes.

1. Republish the old theme if the live store is broken. That's one click and it buys you time.
2. Check the old theme's files. Your custom code is still in it, untouched.
3. Use the code editor's Timeline on individual files if someone edited the new copy and you need an earlier state. Remember it restores one file at a time and can't recover deleted files or asset files.
4. Diff old against new and port the changes properly, then test and republish.

If you deleted the old theme and have no download or Git copy, the custom code is gone. Rebuild it from the diff of what you remember and what the store used to do, and set up a backup routine so it doesn't happen twice.

What I'd do

If your theme is from the Theme Store and you've only used the theme editor and app blocks, update it yourself. Read the release notes, add the draft, click through your key pages on your phone, and publish. It's an afternoon.

If a developer has edited your theme code, I'd treat the update as a small project. Pull the live theme, diff it against a clean copy, decide which customizations still earn their place, and move the keepers into their own files so the next update is easy. On Mahina, the Gurgaon period care brand I built for, the Figma designs went in as their own Shopify sections instead of edits buried in the base theme, and the store kept a 95+ speed score. Custom work kept in its own files is the work an update leaves alone.

If you're not sure what's been changed in your theme or whether the next version will break something, tell me about your store. I'll look at the diff and give you a fixed scope for the update. You can also reach me on the contact page.

Related reads

• Shopify maintenance and retainers: what monthly support covers and costs
• Custom Shopify theme vs premium theme
• What a Shopify store redesign costs in India

Sources

• Shopify Help Center: updating themes
• Shopify Help Center: editing theme code (Timeline, duplicating, update conflicts)
• Shopify Help Center: adding and switching themes (theme library limits, preview links)
• Shopify Help Center: generating theme blocks with AI
• Shopify Help Center: downloading themes
• Shopify Help Center: duplicating themes
• Shopify.dev: Shopify GitHub integration for themes
• Shopify.dev: Shopify CLI theme pull
• Shopify.dev: theme app extensions
• GitHub: Dawn 16.0.0 release notes
• GitHub: Dawn's Custom Liquid section