Shopify themes and design
Shopify custom section development
Sections are the building blocks of a modern Shopify theme. Merchants add, remove and reorder them in the theme editor to build pages without code. When a store needs something no existing section provides, such as a size guide, an ingredients panel or a comparison table, a developer can build a custom section that behaves just like the theme's own.
This page explains how custom sections work, how to design them so your team can use them confidently, and how to keep them working through theme updates.
Illustrative diagram
- Section list — add, remove, reorder
- Custom section — appears like a theme section
- Live preview
- Settings panel — labelled, with defaults
- Repeatable block — such as a table row
- Add block — within sensible limits
What a custom section is
A section is a self-contained file in the theme that defines its layout and the settings merchants can change, such as headings, images, colours and links. Sections can contain blocks: repeatable items such as rows in a comparison table or questions in an FAQ. Shopify's developer documentation notes that JSON templates can render up to 25 sections, each with up to 50 blocks, and that merchants can add, remove and reorder sections in the theme editor.
For a section to be addable from the theme editor, its schema must define presets. Without presets, it can exist in the theme but merchants cannot add it themselves.
Typical custom sections
| Section | Used for | Editable by your team |
|---|---|---|
| Size guide | Fit tables beside the size selector | Table rows as blocks, measurements, notes |
| Ingredients or materials | Product composition and care | Ingredient blocks with name and description |
| Comparison table | Comparing models or bundles | Rows and columns as blocks |
| Shop the look | Products featured in a lifestyle image | Image, product picks, labels |
| Delivery and returns panel | Policies near the buy button | Text, icons, links |
Custom section or app
Custom section
Suits you when
- The feature is mainly about display
- Content is managed in the theme editor or product data
- You want no ongoing subscription
Watch out for
- One-off development cost
- Must be checked when the theme updates
App
Suits you when
- The feature needs its own data or logic, such as reviews or subscriptions
- It must work across themes
- The developer maintains it for you
Watch out for
- Monthly subscription
- Scripts that may affect speed
Designing settings your team can use
Settings
- Only the options people will genuinely change
- Clear labels and help text in the editor
- Sensible defaults so a new section looks right immediately
Blocks
- Repeatable items as blocks, not fixed slots
- Limits that stop layouts breaking
- Block names that show their content in the editor
Content source
- Product-specific content from metafields where it varies by product
- Shared content in section settings where it does not
- Fallbacks when data is missing
Keeping custom sections through theme updates
Because a custom section lives in its own file, it is less likely to conflict with a theme update than edits to the theme's existing files. Shopify's guidance on updating themes says code edits are included in the updated theme if they do not conflict, and otherwise need to be copied across, and it recommends saving a copy of customised code before updating. Keeping custom sections in clearly named separate files, listed in a customisation log, makes that check straightforward.
Signs of a well-built section
Works on every template it is offered on
Tested on the product, collection or page templates where it can be added.
Uses the theme's styles
Inherits fonts, colours and spacing so it looks native, not bolted on.
Accessible markup
Real headings, table markup for tables and keyboard-usable controls.
Light
No heavy scripts for features that only need layout.
Sections and product data together
Some custom sections show the same content everywhere, such as a delivery panel. Others need different content for each product, such as ingredients or measurements. For the second kind, the section can read from product metafields, so each product shows its own data while the layout stays consistent. Planning which approach each section uses avoids sections that must be edited product by product.
Questions about Shopify custom section development
Can our team add custom sections to pages?
Yes, if the section defines presets, it appears in the theme editor's add-section list.
Will a custom section work if we change theme?
Usually it needs adapting to the new theme's styles and structure.
How many sections can a page have?
Shopify's documentation states JSON templates can render up to 25 sections, each with up to 50 blocks.
Can a section show different content per product?
Yes, by reading from product metafields.
Is a section cheaper than an app?
For display features, often over time. For features with their own data or logic, apps are usually better.
Will custom sections slow the store?
Well-built display sections add very little. Heavy scripts should be avoided.
Can you build a section from a design we have?
Yes. Send the design and we will confirm what can be editable.
Sources referenced
Platform features, guidance and rules change. We check the current versions before committing to an approach. This page is general information, not legal advice.
- Shopify.dev: JSON templates (opens in a new tab) — reviewed 2026-10-22
- Shopify Help Center: Updating themes (opens in a new tab) — reviewed 2026-10-22
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