An installed theme can preview successfully while still being incomplete for a specific route. Validate the destination theme against the site content and plugin stack, not only its demo.
Template coverage
- Single posts, pages, archives, search, 404, and pagination.
- Custom post type singles and archives.
- Taxonomy and term archive templates.
- Password-protected, private, empty, and edge-case content.
Site systems
- Header, footer, classic menus, Navigation blocks, and breadcrumbs.
- Forms, search, consent, memberships, ecommerce, and analytics.
- Theme options, widget areas, patterns, template parts, and fonts.
- Page cache, object cache, CDN, optimization, and security plugins.
Quality checks
- Keyboard navigation, focus visibility, labels, contrast, and zoom.
- Responsive behavior at narrow mobile and wide desktop sizes.
- Canonical tags, robots directives, metadata, schema, and heading hierarchy.
- Core Web Vitals and page-weight comparison on representative URLs.
Classic and block themes store different kinds of configuration. Do not assume classic menu locations, widgets, Customizer values, block templates, or Global Styles transfer automatically.