What You Need to Know About WordPress 6.6

By Mike Davey, Senior Editor

The next major release of WordPress, version 6.6, is scheduled to ship on July 16, 2024. It’s not expected to be as developer-centric as WordPress 6.5, but there’s still plenty to get excited about: refinements to existing APIs, community blueprints, and expanded global style variations. In this article, we’ll dive into the most significant updates and changes expected in WordPress 6.6, and some of the enhancements in the latest versions of Gutenberg.

API Enhancements

The Interactivity API and Block Bindings API have garnered a lot of attention since they were introduced in WordPress 6.5, and both are expected to receive enhancements in 6.6. Updates to the Interactivity API won’t be focused on adding new features, but on better test coverage, code quality, error reporting, debugging tools, and bug fixes.

Some enhancements to the Interactivity API were made available with the release of Gutenberg 18.2, including the ability to declare multiple event listeners with data-wp-on for the same event type on the same element, and the Query block has been updated to permit third-party interactive blocks. Gutenberg 18.3 also includes an experimental setting for full-page, client-side navigation through the Interactivity API. This is very cool, but of course it is still experimental and may well break parts of your theme. It’s probably best to take it for a spin in Local or in the WordPress Playground first.

Changes to the Block Bindings API will allow for the editing of connected sources directly from the block, with a goal of potentially making the editor APIs public for 6.6. There’s also some work being done to explore a UI to create bindings, but this likely won’t be complete for WordPress 6.6.

The Block Hooks API, introduced in WordPress 6.4, will continue to evolve with a focus on determining a proper UI for hooked blocks and improving the developer experience. The HTML API will undergo further development, aiming to complete and rely on a custom and spec-compliant encoder/decoder, and design how to communicate when an HTML document has retroactively changed.

If you haven’t used WordPress Playground yet, now would be a great time to give it a shot. An official repository for community-created blueprints for Playground has been established, providing live demos of various WordPress setups.

Say Goodbye to PHP 7.0 and 7.1

Support for these versions of PHP is scheduled to be dropped in WordPress 6.6. PHP 7.2.24 will be supported in 6.6, but the recommended version is 7.4 or later. There isn’t a hard and fast rule about when WordPress drops support for PHP versions, but John Blackbourn outlined the rough process on the Make WordPress blog:

“There’s no concrete usage percentage that a PHP version must fall below before support in WordPress is dropped, but historically the project maintainers have used 5% as the baseline,” he writes. “Now that usage of PHP 7.0 and 7.1 combined is well below that at 2.45%, the process to increase the minimum supported PHP version in this release can move forward.”

Themes and Design

Some of the latest updates include the introduction of negative margin support and experimental full-page, client-side navigation.

Color and Typography Style Variations

Expanded global style variations will allow users to mix and match color and typography sets defined via global style variations. This feature will enable more flexibility and customization options for theme developers. Gutenberg 18.3 introduced a new method of defining color or typography-only global style variations. These will appear under the new Colors and Typography panels in the Site Editor sidebar, rather than as full variations.

Default Font Sizes Setting

A new settings.typography.defaultFontSizes property has been introduced, which will let developers disable the default font sizes from being selectable in the user interface. This fixes a longstanding problem where the Core sizes were shown alongside theme-registered sizes.

Layout Updates

Several updates to layout and related styles have been made, including the introduction of negative margin support and full-page, client-side navigation experiment. These updates will provide more flexibility and customization options for theme developers.

Text Alignment Block Support

A new typography.textAlign support property has been introduced for block developers. The eventual goal is to migrate this feature to core blocks that are using ad-hoc text alignment and support it via global styles.

Post Classes in the Editor

Developers can use the standard post classes (as returned by the get_post_class() function) in the editor as of Gutenberg 18.3. This is only shown when using the Query Loop block and should make it easier to consistently style posts using contextual classes.

Block Fixes

Several issues across various blocks were fixed in Gutenberg 18.2, including the removal of the wrapper <div> from the Latest Posts block in the editor, the addition of missing classes to the front end, and the reduction of CSS specificity of the Pullquote block’s padding and Separator block’s border styles.

Background Image Updates

Gutenberg 18.1 added the initial theme.json support and a UI control for a top-level site background image. As part of some follow-up tasks to round out the feature, Gutenberg 18.2 included a couple of UI updates, including the display of the default background size value as defined in theme.json, and the update of text labels to avoid potential confusion between the background image and color.

Negative Margin Support {#negative margin support}

Negative margins have been made available through the UI controls in the editor. This feature was previously supported via theme.json and custom spacing presets, but is now more accessible to theme users.

Default Theme Updates

Several updates have been made to the default themes, including fixes for font size issues with the Pullquote block, the addition of a wp_is_error() check to prevent a fatal error on PHP 8.0+, and the update of the header to better support the Block Hooks API.

Wrapping Up

Enhancements to APIs seem like the most interesting features coming in WordPress 6.6, but your mileage may vary. What are you most interested in trying out? Let us know in the comments!

About the Author

Mike Davey Senior Editor

Mike is an editor and writer based in Hamilton, Ontario, with an extensive background in business-to-business communications and marketing. His hobbies include reading, writing, and wrangling his four children.