ThemeRouter requires WordPress 6.4 or later and PHP 8.2 or later. Before installation, confirm that the current site is backed up and that the theme you plan to preview or assign is already installed.
Before you install
- Create a current database and file backup.
- Confirm that you can access Plugins, Appearance, and Settings as an administrator.
- Install the destination theme, but do not activate it globally.
- Use staging first when the site has custom rewrites, page caching, or business-critical checkout flows.
Install the plugin
- In WordPress admin, go to Plugins > Add New Plugin.
- Upload the ThemeRouter ZIP file.
- Choose Install Now, then Activate Plugin.
- Open Settings > ThemeRouter and confirm the settings screen loads.
Run a safe first test
Start with Preview Mode on one representative page. Previewing does not create a public assignment; authorized logged-in users see the selected installed theme while visitors continue to receive the normal active theme.
Do not begin with checkout or account pages. First validate a low-risk page, then test templates, navigation, forms, caching, and analytics before expanding the migration.
Next: preview an installed theme
Use a private preview to inspect the destination theme before creating a persistent route.