Technical History of WordPress Development

This technical history is meant to provide a concise summary of what has changed in the codebase with a focus on code that affects how developers write WP core/themes/plugins/blocks. Please visit the posts linked to read more detailed explanations of these functions.


  • What’s New in WordPress 5.3 by Carlo Daniele. Kinsta, 2019.
    • A large number of improvements to Gutenberg including the addition of a Groups block that allows multiple blocks to be grouped together.
    • Addition of PHP register/unregister styles using register_block_style and unregister_block_style.
    • Added recovery_email_debug_info filter to ensure recovery emails include debugging info.
    • Added the site_status_test_result filter.
    • Added admin_email_check_interval filter.
    • Can now resume uploads, better image rotations using EXIF metadata.
    • Added Twenty Twenty theme.
    • Date/Time improvements including addition of wp_timezone_string(), wp_timezone(), wp_date(), current_datetime(), get_post_datetime(), get_post_timestamp().
      • Recommended to stop using date_i18n(), get_post_time(), current_time().
      • Added aria-current="page" attribute.
      • aria_label parameter added to _navigation_markup(), get_the_post_navigation(), get_the_posts_navigation(), et_the_posts_pagination(), get_the_comments_navigation(), get_the_comments_pagination(), the_post_navigation(), the_posts_navigation(), the_posts_pagination(), the_comments_navigation(), the_comments_pagination().
      • Support for rel="ugc" attribute in comments, added to new functions for adding nofollow and ugc values to rel attributes in links: wp_rel_callback(), wp_rel_ugc().
      • Improved REST API by adding support for 'array' and 'object' data types to register_meta() functions. Addition of fields parameter.
  • Updates to Image Processing by Andrew Ozz. WordPress Make, 2019.
    • WP now saves meta data for image sizes before resizing the images.
    • WP now provides a refined largest image instead of actual largest uploaded as largest for use on site.
    • WP_Image_Editor_GD and WP_Image_Editor_Imagick have new methods make_subsize().
    • Addition of wp_get_missing_image_subsizes(), wp_update_image_subsizes(), wp_create_image_subsizes(), wp_get_original_image_path(), and big_image_size_threshold.
  • Kristen Wright. WordPress 5.3 Overview: Top 20 New Features and Improvements. ithemes, 2019.
  • Justin Ahinon. Introducing Handling of Big Images in WordPress 5.3. wordpress make, 2019.