Key Takeaways
- Sections everywhere brings the section/block editor to all page templates — product pages, collection pages, cart, and custom templates can all be customised through the editor without code.
- Native metafields (Admin > Settings > Custom Data) allow merchants to create custom product data fields and display them in OS2 themes without apps or code.
- App blocks change how apps integrate with themes — instead of code injection into theme files, apps provide blocks that merchants add through the editor, improving performance and reducing theme conflicts.
- Dawn is Shopify's reference OS2 theme — free, open source, and the baseline against which other OS2 themes are compared; it's not the most design-rich theme but demonstrates best practices.
- Legacy themes require a rebuild to support OS2 features — the architecture change is fundamental; you can't 'upgrade' a pre-OS2 theme by adding OS2 features to it.
Shopify Unite 2021 brought the most significant update to Shopify's theming system since the platform launched: Online Store 2.0. The update addresses limitations that had frustrated Shopify developers and merchants for years — sections limited to the homepage, metafields requiring apps or code, apps injecting code directly into theme files creating conflicts and performance issues. For merchants, OS2's most visible change is the ability to customise product page layouts through the theme editor without developer help — adding a size guide section, reordering the product information tabs, or displaying custom product data fields visually. For developers, OS2 changes how themes are structured, how apps integrate with themes, and how custom data is connected to template content. This guide explains what OS2 introduces, what it changes about theme development and customisation, and how to assess whether upgrading your current theme is worth the investment.
Definition: JSON Templates vs Liquid Templates in Shopify
Legacy Shopify themes used Liquid (.liquid) template files for each page type — product.liquid, collection.liquid, page.liquid. These files combined HTML, Liquid logic, and section references in a single file. Online Store 2.0 introduces JSON templates (.json) that define a template as a list of sections and their configuration — no HTML or Liquid logic in the template file itself. The actual content and layout is defined by the sections referenced in the JSON file. This separation enables the theme editor to have complete visibility and control over the template's sections — the editor can add, remove, and reorder sections because they're all explicitly declared in the JSON structure. JSON templates are what make 'sections everywhere' possible: the template is essentially a configuration of sections, not a monolithic layout file.
Sections Everywhere and Native Metafields: The Merchant-Facing Changes
For non-developer merchants, sections everywhere and metafields are the most impactful OS2 changes — enabling product page customisation and custom product data display without developer involvement.
In legacy themes, the Shopify theme editor's section customisation was limited to the homepage. Product pages, collection pages, and other templates had fixed layouts — if you wanted to add a size guide table, a care instructions tab, or a trust badge section below the product form, you needed a developer to add the code to the template file, or you relied on apps that injected content through JavaScript (slower, conflict-prone). With sections everywhere in OS2, product pages have the same section management as the homepage — you can add a 'Size Guide' section, an 'FAQ Accordion' section, or a 'Complementary Products' section through the theme editor without touching code.
Native metafields in OS2 unlock a significant use case: displaying product-specific data (ingredients, specifications, care instructions, technical documents) that differs per product, without requiring a separate app for each data type. In Admin > Settings > Custom Data, you create metafield definitions — for example, a 'Ingredients' multiline text field for products, a 'Size Guide' file field, a 'Material Composition' text field. Then in the theme editor, text blocks and sections have a 'Connect dynamic source' option — instead of typing static text, you connect the block to pull from the product's metafield value. Each product can have different metafield values, displayed through the same template section.
App blocks are the third major merchant-facing change. In legacy themes, apps that add content to product pages (review widgets, upsell blocks, trust badges from apps) injected JavaScript and HTML directly into theme template files — creating code conflicts, performance overhead, and complications when themes were updated. In OS2, apps that support app blocks provide their content as theme editor blocks — merchants add them through the editor like native sections. The app's content renders server-side as part of the Liquid render rather than client-side via JavaScript injection, improving page speed and reliability.
- Sections everywhere: add/remove/reorder content blocks on product and collection pages through the editor
- Native metafields: custom product data (ingredients, specs, guides) displayed without code via 'Connect dynamic source'
- App blocks: review widgets, trust badges, and upsell blocks added through theme editor — no code injection
- Product page variants: create multiple product page templates (e.g., one for apparel, one for accessories) with different section layouts
- All OS2 features require an OS2-compatible theme — legacy themes don't support them without rebuild
OS2 and Theme Development: What Changes for Developers
OS2's JSON templates, section schema changes, and app block API change how Shopify themes are built and maintained — requiring a different approach to template structure and app integration.
The practical implication of JSON templates for developers: each page type can have multiple template variations, each with a different section configuration. A store can have product.json (default product template), product.apparel.json (apparel-specific template with a size chart section), and product.preorder.json (preorder template with a preorder notice section) — all managed through the theme editor. The templates directory now contains both .liquid files (for complex templates that need Liquid logic) and .json files (for editor-managed templates). Most new template development in OS2 targets JSON templates.
Sections in OS2 still use Liquid and schema but with expanded capabilities. Sections can include 'blocks' — sub-elements within the section that can be added, removed, and reordered independently. The section schema now supports 'limit' and 'type' for blocks, and sections can declare they accept 'app' blocks (allowing third-party app blocks to appear within the section). Sections are stored in the sections/ directory and referenced from JSON templates — the separation of template structure (JSON) from section rendering (Liquid) is the core architectural change.
Experience Signal
The OS2 migrations that add the most value for merchants are the ones where product page customisation was previously a constant developer request — merchants who wanted to show different information tabs, size guides, and trust badges on different product templates were either maintaining expensive theme customisations or using multiple conflicting apps. After OS2 migration, those merchants can manage their product page layouts through the editor. The migrations that are hardest are heavily customised legacy themes where significant development work was done to add features that OS2 now provides natively — the rebuild cost is the full cost of recreating all the custom functionality in the new architecture.
Frequently Asked Questions
In legacy Shopify themes (pre-OS2), sections — the customisable content blocks in the theme editor — were only available on the homepage. Product pages, collection pages, and other templates had static layouts that could only be changed by editing theme code. 'Sections everywhere' in Online Store 2.0 extends the section and block system to every page template — product pages, collection pages, blog posts, cart, and custom page templates all support sections. This means merchants can add, remove, and reorder content blocks on any page through the theme editor without touching code. App blocks (a new OS2 feature) are sections specifically provided by Shopify apps — a review app can add a Review Stars block to any product page template through the editor, rather than requiring code injection.
Metafields are custom data fields attached to Shopify resources (products, variants, collections, customers, orders). Before OS2, metafields existed but required third-party apps or custom Liquid code to display them in themes. In OS2, metafields are a native part of the admin interface — you can create metafield definitions (e.g., 'Ingredients' text field for products, 'Size Guide' file field, 'Fabric Composition' text field) in Admin > Settings > Custom Data, and then use the theme editor's 'Connect dynamic source' feature to display that metafield's value in any section or block on the product page. This enables displaying product-specific data (care instructions, specifications, custom tabs) without custom code or apps, directly from the theme editor.
Upgrading depends on your situation: If you're using a legacy theme (pre-OS2) with significant customisation, upgrading to an OS2-compatible theme involves rebuilding those customisations in the new theme architecture — it's essentially a theme rebuild project, not a simple update. If you're using a theme marketplace theme that has released an OS2 version (Dawn, Debut's replacement, Turbo, Prestige, etc.), check whether the theme developer provides an upgrade path — some do, some require starting fresh. The benefits of OS2 are most valuable for merchants who: want section customisation on product pages without developer help, plan to use native metafields for product data, or rely on apps that have released OS2 app blocks for cleaner integration. If your current theme works well and you don't need those specific features, the upgrade isn't urgent.
Sources
Want to Upgrade to Shopify Online Store 2.0?
Webnixon migrates existing Shopify themes to OS2 — rebuilding customisations in the new architecture, configuring metafields, and setting up the section layouts that match your store's product presentation needs.
Book a Shopify ConsultationAbout the author
David Okafor
Developer
David is a full-stack developer at Webnixon with expertise in React, WordPress, and custom web application development. He contributes to complex front-end builds, API integrations, and performance-focused engineering for Webnixon clients. He writes about web development best practices, WordPress, and the technical side of building fast, maintainable websites.
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