WordPress Block Themes and Full Site Editing: A Business Owner's Guide

WordPress block themes are themes built entirely from blocks, which you can edit visually in the site editor, including headers, footers and page templates. They are WordPress's modern approach to building sites, often called full site editing, and they replace the classic model where layouts lived in PHP template files. For many new business sites they are now the sensible default. For existing sites, switching is a real project, so it is worth knowing what you gain before you start.

This guide explains classic versus block themes, how the site editor works, templates, patterns and styles, the pros and cons for business sites, whether to switch and how much effort migration takes.

Classic vs block themes

Classic themes define layouts in PHP template files. You change content in the editor, but headers, footers and templates are controlled by code or by theme settings, and page builders often fill the gap.

Block themes define layouts as block templates. Headers, footers, page templates and archive layouts are all made of blocks and can be edited in the site editor. Global design settings, such as colours, typography and spacing, are defined in a theme.json file and adjustable through Styles.

How the site editor works

The site editor, found under Appearance, Editor in block themes, lets you edit:

• Templates: the layouts for pages, posts, archives and search results.
• Template parts: reusable sections such as the header and footer.
• Patterns: pre-designed groups of blocks that editors can insert.
• Styles: colours, typography and spacing across the whole site.
• Navigation: menus built as blocks.

The WordPress site editor documentation explains each area. Changes made in the site editor are stored in the database, so they survive theme updates.

Templates, patterns and styles

These three ideas do most of the work:

• Templates control the overall layout of each type of page.
• Patterns give editors ready-made sections, such as a service card grid or a testimonial block, that match the brand. Synced patterns update everywhere when the pattern changes, and pattern overrides let editors change content within a locked design.
• Styles define the design system once, so every block uses the same colours, fonts and spacing.

For business sites, patterns are the key benefit. A developer can create a set of approved sections for service pages, case studies and landing pages, and editors can build new pages from them without drifting off-brand.

Pros for business sites

• No page builder licence to renew, and less dependence on third-party plugins.
• Lighter pages than most page builder sites, because core blocks output leaner code.
• Consistent design through theme.json and patterns.
• Visual editing of headers and footers without code.
• Future-proofing, because this is the direction WordPress itself is investing in, including in WordPress 7.0.

Cons and rough edges

• A learning curve for editors who are used to page builders or classic themes.
• Some design effects still need a developer, through custom blocks or CSS.
• Plugin compatibility: some older plugins assume a classic theme.
• Site editor changes in the database can make version control and deployment trickier, so changes should be managed carefully on larger sites.
• Migration effort for existing sites, covered below.

Should you switch?

• New site: a block theme, ideally custom-built with patterns for your content, is usually the best starting point.
• Classic theme that works well: there is no urgency. Plan a switch for your next redesign.
• Page builder site that is slow or fragile: a move to a block theme can bring real speed and maintenance gains, but it is a rebuild of templates rather than a setting change. Our comparison of WordPress page builders covers the trade-offs.
• Heavily customised classic theme: weigh the rebuild cost against the benefits, and consider waiting for a redesign.

Migration effort

Moving to a block theme means rebuilding templates and template parts as blocks, recreating key layouts as patterns and checking every important page. As a rough, indicative guide from projects of this kind:

• Small brochure site, five to ten templates: often around one to two weeks of work, including testing.
• Larger business site with many custom layouts: several weeks, depending on how many unique designs exist.
• Sites with WooCommerce or complex plugins: longer, because shop templates and plugin compatibility need extra testing.

These estimates assume the content itself stays largely the same. If you are also rewriting pages or changing the site structure, plan that as a separate piece of work. Protect SEO during migration: keep URLs the same, check that titles, headings and schema survive, and compare key pages before and after launch. Our guide to WordPress child themes explains how child themes work with block themes, which helps when customising a parent block theme. For the bigger picture, see WordPress for business, and when you need custom blocks or functionality, our guide to custom WordPress plugin development. You can see our WordPress work on our web development and custom WordPress plugins pages.

Frequently asked questions

Planning a move to blocks?

If you are weighing up a switch, ask us for a migration estimate based on your current theme and templates.