Shopify theme customization

Theme editor or code edits

Why the difference matters for updates

Theme developers release updates with fixes and new features. Shopify's documentation explains that when you add an updated version of a Theme Store theme, customisations made in the theme editor are copied over and applied to the updated theme. Code edits are included only if they do not conflict with the update; otherwise you need to copy them into the new version yourself. Shopify advises saving a copy of any customised code before updating.

This is why experienced developers do as much as possible through the editor and keep code edits small, contained and documented.

What the theme editor can usually handle

When code is the right answer

Some changes are beyond any theme's settings: a custom section for size guides, a product comparison table, special handling for bundles, or a layout the theme simply does not offer. These need code. The cleanest approach is usually to add new section files rather than rewrite the theme's existing ones, because new files are less likely to conflict with future updates.

Shopify's own guidance is to edit theme code only if you know HTML and CSS and have a basic understanding of Liquid.

Customising safely

1. 01

   Duplicate first

   Shopify recommends making a backup copy of a theme before customising it.

   Output: Backup theme

2. 02

   Editor before code

   Exhaust the theme's settings and sections before writing code.

   Output: Editor changes

3. 03

   Contained code

   New sections or snippets where possible, with comments marking custom work.

   Output: Custom files

4. 04

   Change log

   A list of every code change, file and reason, kept with the store.

   Output: Customisation record

Problems with unmanaged customisation

• Updates that are never applied

  Too many scattered code edits make updating so risky that the theme falls behind.

• Leftover app code

  Code added by apps removed long ago can slow pages or cause errors.

• Nobody knows what was changed

  Without a record, every new developer must rediscover the customisations.

Templates for different products

Many stores need different layouts for different products: a clothing item with a size guide, a gift card with no shipping information, a bundle with its own explanation. Modern themes let you create alternative product templates in the editor and assign them to specific products, which often removes the need for code altogether. Shopify's developer documentation notes that JSON templates can render up to 25 sections, each with up to 50 blocks, which is ample for most product layouts.