Preview a theme with theme dev

theme dev starts the local theme server and opens the hosted Theme Workbench using the connected development store.

Command

upstorr theme dev my-brand-theme

Keep this terminal process running while you preview. The default local server uses 127.0.0.1:3210.

Useful local flags are:

upstorr theme dev my-brand-theme --port 3211
upstorr theme dev my-brand-theme --host 127.0.0.1 --no-open

--no-open prints the Workbench URL instead of opening it. The URL contains a short-lived launch value, so do not publish or share it.

What happens

Before opening Workbench, the CLI resolves the selected theme, verifies its saved store connection, prepares the local state and starts the preview server. Workbench then combines:

  • the theme files on your computer;
  • the connected store's permitted development data;
  • the current draft design state;
  • the public versioned runtime contract.

Edits stay local until you deliberately upload a version. theme dev never publishes the live storefront.

Test before upload

Check every route your theme supplies, including mobile and desktop. Test product variants, cart changes, checkout, sign-in, orders, wishlist, bookings and digital delivery when your theme presents them. Also test loading, empty and error states.

Common problems

  • No active connection: run theme connect first.
  • Port already in use: pass another --port.
  • Workbench says local preview authorization failed: stop old preview processes and launch Workbench again from the current CLI command. Do not reuse an old launch URL.
  • The editor loads but the preview does not: read the terminal error, then run theme check. Invalid Liquid, missing generated support or a browser bundle error can stop the preview.
  • Store data looks wrong: confirm the connected store and storefront shown after theme connect.