Check the theme's maintenance history, compatibility information and required companion plugins. Decide whether you want a block theme, which supports the Site Editor, or a classic theme with a different customisation workflow. Demo screenshots may use premium extras or imported content that are not included in a basic installation.

1. Sign in as an administrator and open Appearance > Themes > Add New Theme. On Multisite, theme installation is controlled by the network administrator.
2. Search for the theme and review its details. Confirm the author and exact name before selecting Install.
3. Use the available preview option, or activate the theme on a staging copy for a realistic test with your own content.
4. Review headers, navigation, typography, featured images, forms and mobile layouts. Configure the theme through the controls it supplies.
5. When ready, make a backup and activate the tested theme on the intended live site.

Open the public site while signed out. Check pages with different layouts and complete any important enquiry or shopping workflow in a suitable test mode. Purge affected caches so visitors receive the current styles.

Your posts and pages normally remain in the database, but theme-specific templates, widgets, shortcodes or settings may not transfer to another theme. Keep the previous theme until you have checked the result and know whether it is needed for rollback or as a child theme's parent.

Record the error instead of repeatedly uploading alternative copies. Permissions, storage limits or an incompatible package can prevent installation. If the Add New control is missing, check your user role or Multisite restrictions. Avoid downloading a renamed copy from an unknown website just to bypass an installation problem.

• Uploading and installing a WordPress theme ZIP file
• Deleting an unused WordPress theme safely
• Changing your WordPress theme and planning a redesign
• Changing global typography in a block theme

• Working with themes
• Themes screen