ThemeRouter has two distinct workflows. Preview Mode is for private inspection. Theme Set Mode is for routing matched public requests to an installed theme.
| Decision | Preview Mode | Theme assignment |
|---|---|---|
| Audience | Authorized logged-in users | All visitors to the matched route |
| Duration | Temporary | Persistent until changed or removed |
| SEO impact | Not public | Can change markup, metadata, and performance |
| Best use | Review and approval | Controlled rollout |
| Rollback | Exit the preview | Remove or change the assignment |
Use Preview Mode when
- You are comparing installed themes.
- A client or stakeholder needs to inspect a design privately.
- You are validating templates against current production content.
- You are not ready for visitors to receive the new theme.
Use a theme assignment when
- The matched route has passed functional, SEO, accessibility, and performance checks.
- The team has a rollback owner and a known previous value.
- Anonymous-user and cache behavior have been tested.
- The rollout scope is intentionally limited and measurable.
Start with the smallest route
Assign one low-risk page or post before applying a theme to a complete post type or taxonomy.