Block Themes vs Classic Themes: Which Is Right for Your WordPress Site?

If you have looked at a new WordPress theme recently, you may have noticed the language has shifted. Themes are now described as either block themes or classic themes, and the two work in genuinely different ways under the surface, not just in name.

This matters more than it might seem at first, because the theme you choose affects how the site is built, how easily it can be customised, and how well it fits where WordPress is heading. This article explains what each type actually is, then works through the practical pros and cons of both so you can make an informed choice.

What Is a Classic Theme?

A classic theme is the traditional WordPress approach, and most WordPress sites still use it today. It relies on PHP template files, a defined template hierarchy, and a functions.php file to control how the site is structured and styled. Customisation beyond what the theme options allow typically means editing code directly or relying on a page builder plugin layered on top.

Widgets and menus are managed through their own separate screens, distinct from the main content editor. This separation is familiar to anyone who has used WordPress for a few years, and it underpins most of the WordPress plugin and theme ecosystem as it exists today.

What Is a Block Theme?

A block theme is built entirely from blocks, using the Gutenberg block editor for every part of the site, not just post and page content. Headers, footers, templates and site-wide styling are all controlled through the Site Editor, using a theme.json file to define colours, typography and layout settings in a structured, editable way.

Instead of editing PHP template files to change a page’s layout, you edit templates visually in the same block editor you use to write a post. This is a meaningfully different way of building a site, and it reflects the direction WordPress has been moving in since full site editing was introduced.

Classic Themes: Pros and Cons

Advantages

• Mature and stable, with years of refinement and a huge number of themes to choose from
• Broad compatibility with plugins, many of which were built with the classic template structure in mind
• Deep customisation is possible for anyone comfortable editing PHP, with a well-documented template hierarchy
• Familiar to most WordPress developers, which can make it easier to find support or hire help

Disadvantages

• Meaningful customisation beyond theme settings usually requires code or a separate page builder plugin
• Page builders added on top can bloat a site with extra CSS and JavaScript, affecting page speed
• Editing the header, footer or template structure is not accessible to non-technical site owners without help
• Increasingly positioned as the legacy approach as WordPress core development focuses on block themes

Block Themes: Pros and Cons

Advantages

• The entire site, not just individual posts, can be edited visually in the Site Editor without touching code
• Global styling through theme.json keeps colours, typography and spacing consistent without extra plugins
• No separate page builder is generally needed, which tends to mean a leaner, faster site out of the box
• Aligned with the direction of WordPress core, so block themes benefit from ongoing native development

Disadvantages

• The block theme ecosystem is younger, so the choice of polished, well-supported themes is narrower than for classic themes
• Some older or more specialised plugins were built with classic templates in mind and may not integrate cleanly
• The Site Editor has a learning curve of its own, and can feel unfamiliar to anyone used to the classic workflow
• Highly bespoke or unusual layouts can sometimes be harder to achieve purely through blocks without custom code

Which Should You Choose?

For a new site built from scratch, with no legacy plugin dependencies to worry about, a block theme is generally the more future-facing choice. It gives a site owner more genuine control without needing a developer for every small change, and it fits with where WordPress is clearly headed.

For an established site that relies on plugins built for the classic structure, or where a developer needs precise, code-level control over layout, a classic theme, or a well-built classic theme paired with a lightweight page builder, often remains the more practical option in the short term.

Neither is objectively wrong. The right choice depends on what the site needs to do, who will maintain it day-to-day, and how much the decision needs to account for existing plugins and workflows.

Things to Check Before You Decide

☐  Whether your key plugins are confirmed to work well with full site editing and block themes

☐  Who will be making day-to-day content and design changes, and how comfortable they are with each editing approach

☐  Whether the site needs a highly bespoke layout that may be easier to achieve with custom PHP templates

☐  How mature and well-supported the specific block theme you are considering actually is

☐  Whether you are building new or migrating an existing site with established customisations

Frequently Asked Questions

Can I switch from a classic theme to a block theme later?

Yes, but it is not always a simple swap. Content created in posts and pages generally carries over well, but headers, footers, widgets and any custom template work will usually need to be rebuilt in the Site Editor. It is worth planning the switch properly rather than treating it as a quick theme change.

Do block themes work with page builder plugins?

Some do, though the appeal of a block theme is that a separate page builder often becomes unnecessary, since the Site Editor already provides visual control over layout. Mixing a block theme with a full page builder plugin can sometimes cause conflicts or duplicate functionality, so it is worth checking compatibility first.

Are block themes faster than classic themes?

Not automatically, but they often end up faster in practice because they reduce the need for extra plugins and page builder scripts that can slow a site down. A well-built classic theme without a heavy page builder can still perform very well, so the theme type itself is only part of the picture.

Is full site editing only available with block themes?

Yes. Full site editing, meaning the ability to edit headers, footers and templates directly in the block editor, is a feature of block themes specifically. Classic themes can still use blocks within post and page content, but the wider site structure remains controlled through PHP templates rather than the Site Editor.

Will classic themes stop being supported?

Not in the foreseeable future. WordPress has a strong track record of maintaining backwards compatibility, and classic themes remain fully supported and widely used. That said, WordPress core development is clearly focused on full site editing, so block themes are likely to become the more actively developed path over time.

Not Sure Which Theme Approach Suits Your Site?

If you are planning a new WordPress site or considering a switch and want a clear recommendation based on your actual plugins and workflow, get in touch for a straightforward conversation with no obligation and no sales pitch.