# Use the Shopify theme editor

Find your way around the Shopify theme editor.

Open it from **Online Store > Themes** by choosing **Customize** on a theme.

* **The page picker** at the top switches between templates: home page, products, collections, blog posts, pages and more.
* **Sections** sit on the left. Add, hide, reorder and remove them. Each section has settings, and many hold blocks you can add and arrange.
* **Theme settings** (the brush icon) holds store-wide choices: colors, fonts, presets, and Gatefold's release data and pre-order settings.
* **App embeds** turn on app features that sit across the whole store.
* **Preview sizes** at the top switch between desktop and mobile.

Changes stay in the editor until you choose **Save**. Saving a published theme puts the changes live at once, so try big changes on an unpublished copy first.

Shopify's guide to the [theme editor](https://help.shopify.com/manual/online-store/themes/customizing-themes) has more detail.