Key takeaways
- Your posts and media live in WordPress, not the theme, so your content carries over when you switch.
- Theme-specific features — breadcrumbs, custom blocks, shortcodes — are what you will need to replace.
- Migrate gradually: switch on a staging copy, rebuild key layouts as block patterns, then cut over.
What carries over
The reassuring part first: your articles, pages, media, categories and tags all live in the WordPress database, independent of the theme. Switching themes does not delete or move any of that. When you activate a new theme, your existing content is still there — it just gets styled differently.
What breaks when you switch
The things tied to the old theme are what you have to plan for. Theme-specific blocks and shortcodes stop rendering and leave placeholder text. Features the theme provided — breadcrumbs, a particular hero layout, review or comparison boxes — disappear. Theme-level SEO or design settings do not transfer. None of this is your content; it is presentation the old theme owned.
- Theme shortcodes and custom blocks (they render as raw text once the theme is gone).
- Breadcrumbs, if the theme supplied them.
- Theme design settings, custom colors and layout options.
- Any SEO fields the theme added rather than a plugin.
Plan the migration
Do it on a staging copy, not live. Inventory the theme-specific features you rely on, and map each one to a replacement — a core block, a block pattern, or a plugin. Rebuild your most important layouts (home, a typical post, a comparison) as block patterns so they are reusable. Only then switch the live site.
After the switch
Once you are on the block theme, re-add the pieces the old theme provided: breadcrumbs via a theme-independent plugin, SEO meta via a focused plugin, and any comparison or review layouts as patterns. Walk through your key templates to confirm everything renders.
PressHangar Starter is a lightweight block theme built for exactly this landing spot, with genre heroes, comparison and review patterns, and disclosure patterns already included.
Frequently asked questions
- Will I lose my articles when I change themes?
- No. Your content lives in the WordPress database, independent of the theme, so it stays put. Only the styling changes.
- What happens to theme-specific blocks and shortcodes?
- They stop rendering and can leave placeholder text behind. Replace them with core blocks or patterns before you remove the old theme.
- Should I switch on the live site?
- Better not. Test on a staging copy, rebuild the key layouts, and then cut over so visitors never see a half-migrated site.