✅ How to Enable the Gutenberg Editor for Custom Post Types in WordPress (2025 Guide)

Back in the early days of Gutenberg (around 2018–2019), many developers were caught off guard by how it interacted with Custom Post Types (CPTs). A common issue? You’d register a CPT, but it would stubbornly load the Classic Editor instead of the sleek new block editor.

Fast-forward to 2025: Gutenberg is now the default and powerful editing experience in WordPress. So if you’re still seeing the classic editor when editing a CPT, it’s time to bring your code up to speed.

Let’s go over how to properly enable the Gutenberg (block) editor on a custom post type today.

🛑 The Problem (Classic Editor Appears Instead of Gutenberg)

Here’s a sample of an older CPT registration function that still results in the Classic Editor:

function create_posttype() { register_post_type( 'companies', array( 'labels' => array( 'name' => __( 'شرکتهای عضو' ), 'singular_name' => __( 'شرکت' ) ), 'supports' => array('title', 'editor', 'custom-fields', 'excerpt', 'thumbnail'), 'public' => true, 'has_archive' => true, 'rewrite' => array('slug' => 'companies'), ) );
}
add_action( 'init', 'create_posttype' );

Looks fine, right? The 'editor' support is there. But still — no Gutenberg. Why?

✅ The Solution: Add `show_in_rest => true`

To make Gutenberg work, two conditions must be met:

'editor' must be included in the supports array (you already have this ✅).
Most importantly: 'show_in_rest' => true must be present. This makes the post type accessible via the REST API — a requirement for Gutenberg.

✅ Updated and Correct Code:

function create_posttype() { register_post_type( 'companies', array( 'labels' => array( 'name' => __( 'شرکتهای عضو' ), 'singular_name' => __( 'شرکت' ) ), 'supports' => array('title', 'editor', 'custom-fields', 'excerpt', 'thumbnail'), 'public' => true, 'has_archive' => true, 'rewrite' => array('slug' => 'companies'), 'show_in_rest' => true, // 👈 This line enables Gutenberg ) );
}
add_action( 'init', 'create_posttype' );

And that’s it. No need for complex filters or hacky workarounds.

🧠 Why `show_in_rest` Matters

The block editor (Gutenberg) is a React-based application that relies heavily on the WordPress REST API to function. If your custom post type doesn’t support show_in_rest, the editor can’t fetch or manage its data in the expected way — so WordPress falls back to the Classic Editor.

🚀 Bonus: Customizing Further

Once Gutenberg is enabled, you can:

Add custom blocks with block.json
Use block templates for structure
Create block variations specific to your CPT

You’ve now opened the door to a fully modern editing experience!

✅ Final Checklist for Gutenberg-Ready CPTs

Make sure your register_post_type() call includes:

'supports' => array('editor', ...)
'show_in_rest' => true

And you’re good to go! 💪

🧩 Useful Resources

Have questions or want to take your CPTs to the next level with block patterns or full site editing? Drop a comment below or reach out — let’s build the future of WordPress together. 🌐