WordPress 6.3 and 6.3.1 – Update Notes

WordPress 6.3 and 6.3.1
WordPress version 6.3 was released on August 8th, 2023 and was followed by the release of 6.3.1 on August 29th, 2023. This version of WordPress marks the end of support for PHP version 5.6.

What is a WordPress Release Series?

A release series is a group of WordPress versions that share a common major version number. WordPress, like many software applications, follows a versioning scheme that includes three parts: major version, minor version, and patch version.

  • A major version usually indicates significant changes and new features in the software.
  • A minor version usually has smaller feature enhancements, improvements, and bug fixes.
  • A patch version focuses on fixing bugs, addressing security issues, and maintaining stability.

WordPress 6.3 Update Executive Summary

In WordPress 6.3, they’re introducing a wave of enhancements and improvements across the board. Whether you’re a developer, site administrator, or user, there’s something here for everyone. We’ve categorized the changes and updates to help you navigate the exciting improvements.

Key Categories of Improvements

Here’s a breakdown of the major categories of improvements and what you can expect in WordPress 6.3:

WordPress 6.3 brings in 10 Gutenberg releases into the core, introducing new Block APIs, Block properties, and more.

They've dropped support for Internet Explorer scripts and made important changes to bundled themes.

Enjoy greater control over caching, including setting expiration times and implementing custom cache strategies.

We now support hidden files and offer more control over list_files().

Say goodbye to PHP 5 - WordPress 6.3 requires PHP 7.0.0 or higher for better performance and security.

Faster translations and improved load times for multilingual sites.

Automatic image optimizations for faster load times and better performance.

Significant improvements in lazy loading for various metadata types.

Enhanced query performance and optimizations for smoother site experiences.

Developers can now register scripts with "async" and "defer" attributes for better control over loading.

Improved reliability during updates and new checks to troubleshoot updates effectively.

Caching improvements for database queries in WP_User_Query, enhancing user experience.

Various updates, including a more efficient Cron API, expanded Block pattern filtering, new oEmbed providers, and more.

WordPress 6.3.1 Update Executive Summary

WordPress 6.3.1 is a minor release focused on maintenance and bug fixes. Here’s a concise overview of what you need to know:

Maintenance Updates

  • This release includes 4 bug fixes in the Core of WordPress.
  • The block editor receives attention with 6 bug fixes, ensuring a smoother editing experience.


  • Several WordPress packages have been updated, enhancing the platform’s functionality and stability.
  • Notable updates include @wordpress/block-directory, @wordpress/block-editor, @wordpress/block-library, @wordpress/core-commands, @wordpress/core-data, and more.

List of Files Revised

  • The update also includes revisions to important files, ensuring WordPress operates smoothly and efficiently.
  • Key files like package-lock.json, package.json, /wp-admin/about.php, /wp-admin/includes/class-wp-site-health.php, and others have been revised to maintain the integrity of the platform.

WordPress 6.3.1 is a focused release aimed at enhancing the overall user experience by addressing critical bugs and improving the stability of the block editor. As always, keeping your WordPress installation up-to-date ensures a secure and reliable website.

Potential Impacts to Your Site

Upgrading to WordPress 6.3 or 6.3.1 brings various improvements and bug fixes, but it’s essential to understand the potential impacts, both positive and negative, before making the transition:

Positive Impacts:

  1. Enhanced Features: WordPress 6.3 and 6.3.1 may introduce new features and improvements, offering better functionality and user experience. This can enhance the overall quality of your website.
  2. Security: Upgrading ensures that your site benefits from the latest security patches and improvements, reducing the risk of vulnerabilities that could be exploited by malicious actors.
  3. Bug Fixes: These releases address numerous bugs, potentially resolving issues that may have affected your site’s performance or functionality.
  4. Performance: Performance improvements in WordPress core and various packages may lead to faster load times and a more responsive website.

Negative Impacts:

  1. Compatibility Issues: Some plugins, themes, or custom code may not be fully compatible with the new version. This can lead to functionality issues or even site crashes. It’s essential to check the compatibility of your existing components before upgrading.
  2. Plugin and Theme Updates: The upgrade may require updates to your plugins and themes to ensure compatibility. Failing to update them could lead to conflicts or broken functionality.
  3. Custom Code: If your site relies heavily on custom code, it might require adjustments to work correctly with the new version. Failure to update custom code can result in errors or deprecated functionality.
  4. Learning Curve: New features or changes in the user interface may require users and administrators to adapt and learn. This might temporarily slow down content management or require additional training.

Best Practices for a Smooth Upgrade:

  1. Backup: Always back up your site before upgrading to WordPress 6.3 or 6.3.1. This ensures you can restore your site if any issues arise.
  2. Check Compatibility: Verify that your themes, plugins, and custom code are compatible with the new version. Visit the WordPress plugin and theme directories for updates and compatibility information.
  3. Test in Staging: If possible, test the upgrade in a staging environment to identify and address any compatibility issues without affecting your live site.
  4. Update Everything: Ensure that your themes, plugins, and custom code are up to date before upgrading to the new version of WordPress.
  5. Monitor and Troubleshoot: After upgrading, closely monitor your site for any issues. Be prepared to troubleshoot and resolve problems promptly.

In conclusion, while upgrading to WordPress 6.3 or 6.3.1 can bring significant benefits in terms of security, performance, and bug fixes, it should be approached with caution. Careful preparation, including compatibility checks and backups, is crucial to mitigate potential negative impacts and ensure a smooth transition.

Security Notes

[table id=1 /]

WordPress 6.3 and 6.3.1 were released, introducing significant improvements and bug fixes. The major categories of improvements in WordPress 6.3 include enhancements to the Block Editor, Cache API, PHP support, and more. WordPress 6.3.1 is a minor release focused on maintenance and bug fixes. Upgrading to these versions can bring enhanced features, security, bug fixes, and performance improvements, but it’s important to consider potential compatibility issues and prepare accordingly. The document also provides a list of security vulnerabilities in various plugins that have been patched.