Polaris 2.0 Release Candidate: What Shopify Developers Need to Know

Shopify’s admin UI is getting a fresh look, and the Polaris 2.0 release candidate (RC) is the first chance for app developers to see it in action. Available today for embedded App Home interfaces, the RC mirrors the new color palette, typography, spacing, and icons that will roll out to merchants starting September 15, 2026. In this post we break down the visual changes, who they affect, and the exact steps you need to take to stay compatible.

Why Polaris 2.0 Matters Now

Polaris is the design system behind every Shopify admin screen. When Shopify ships a new visual language, apps that still load the old polaris-1.js will look out of place, potentially confusing merchants and hurting conversion rates. The RC gives you a sandbox to test the new look side‑by‑side with the legacy design, ensuring a seamless transition before the mandatory update deadline for Built for Shopify apps on May 1, 2027.

How the Visual Changes Appear

When you load polaris-2.0-rc.js inside the Shopify admin, the components automatically detect the host store’s design mode. In a shop that has already switched to the new admin, components adopt the fresh palette, rounded corners, and updated icon set. In a shop still on the old admin, the same components retain the classic look, so a single codebase can serve both cohorts without conditional logic.

Who Is Affected: Developers vs. Merchants

Merchants see the new UI only when Shopify finishes its progressive rollout. Developers, however, need to ensure their embedded apps render correctly in both environments. If you’re using Polaris React, you’ll need to migrate to Polaris Web Components first; if you already use Web Components, simply swap the CDN URL. Extensions (App Home UI, Admin UI) update automatically and require no code changes.

Step‑by‑Step Migration Guide

Update the CDN reference – Replace any existing Polaris script tag with the RC URL:

<script src="https://cdn.shopify.com/shopifycloud/polaris-2.0-rc.js"></script>

Verify component rendering – Open your app in a store that has the new admin design (request a test shop from Shopify if needed) and confirm that colors, spacing, and icons match the screenshots in the RC docs.

Test the fallback – Open the same app in a store still on the legacy admin. Components should look unchanged, proving the dual‑mode behavior works.

Migrate from Polaris React – If you’re on React, follow the official migration guide. Start with Page, Section, and Button components, as they have the biggest visual impact.

Check safe‑area insets – For sticky footers or floating bars, use the CSS variable --shopify-safe-area-inset-bottom provided by the Environment API to avoid the new Sidekick bar overlapping your UI.

Run automated UI tests – Update any visual regression suites to capture both design states.

Deploy to a staging shop – Once tests pass, push the changes to production.

Testing Across Admin Versions

Shopify does not expose a toggle to force the new design on a store, so the most reliable method is to test on two separate development stores: one that has opted into the new admin (you can request early access via the Shopify Partner Dashboard) and another that remains on the classic UI. Outside the admin, loading the RC script renders the new style by default, giving you a quick visual sanity check without needing a shop at all.

Special Considerations for Built for Shopify Apps

If your app is listed in the Shopify App Store under the “Built for Shopify” program, you have a hard deadline: update your embedded App Home to Polaris 2.0 by May 1, 2027. The RC lets you spread the work over the next year, testing in real‑world merchant environments as the rollout proceeds. Missing the deadline could result in a compliance warning or removal from the store.

Handling Fixed or Sticky Content

The new admin introduces a floating Sidekick bar at the bottom of the viewport. To keep your footer, toast notifications, or sticky action bars visible, read the Environment API docs and apply the CSS variable:

padding-bottom: var(--shopify-safe-area-inset-bottom);

This ensures your content respects the safe‑area inset on both old and new admin versions.

Extensions Update Automatically

Admin UI extensions and App Home UI extensions inherit the appropriate visual style automatically—no code changes are required. Their functionality remains identical, so you can focus on UI polishing rather than rewriting extension logic.

Next Milestones and Deadlines

September 15, 2026 – Progressive rollout of the new admin to merchants begins.

May 1, 2027 – Built for Shopify apps must be fully migrated to Polaris 2.0.

Ongoing – Keep an eye on the Developer Changelog for any patch releases to the RC, and update the CDN URL to the stable version once it’s published.

Conclusion & Next Steps

Adopting Polaris 2.0 today gives you a head start on visual consistency, reduces last‑minute migration risk, and shows Shopify merchants that your app is modern and well‑maintained. Replace the script tag, run the dual‑environment tests, and update any React components according to the migration guide. Need help or want a code review? Drop a comment below or join the #shopify-dev channel on Discord. Your smooth transition starts now!