Mixed (others) (category)
| add_admin_bar_menus | Fires immediately after WordPress creates the basic admin bar items. |
| after_menu_locations_table | Fires after the table on the Appearance → Menus → Manage Locations admin tab, allowing HTML to be output. |
| comment_class | Allows you to change the list of CSS classes applied to each comment |
| cron_schedules | Allows you to add a new time interval for Cron tasks (schedules). |
| doing_it_wrong_trigger_error | Allows you to prevent an error from being generated when _doing_it_wrong() is called. |
| phpmailer_init | Allows you to configure authenticated SMTP email delivery. Fires after |
| pre_http_request | Allows you to short-circuit an HTTP request and return a specified value. |
| register_new_user | Fires after a new user is registered, allowing an action to be performed. |
| show_admin_bar | Allows you to show or hide the admin bar (toolbar) on the front end. The hook works only on the front end; it does not work in the admin area. |
| user_trailingslashit | Allows you to remove/add a trailing slash ( |
Basic (main)
| after_setup_theme | Fires on every page load immediately after the theme is initialized. It is normally used to set up basic theme features; see add_theme_support(). |
| init | Fires after WordPress has finished loading but before any HTTP headers are sent. |
| plugins_loaded | Fires immediately after all active plugins have loaded. |
WP_Query
| ajax_query_attachments_args | Allows you to change the parameters passed to WP_Query during an AJAX request for media files (attachments). |
| post_limits | Changes the LIMIT clause of the SQL query before posts are retrieved from the database by WP_Query. |
| post_search_columns | Allows you to change the list of columns searched when using the |
| posts_where | Allows you to change the WHERE clause of an SQL query used to retrieve posts with WP_Query. |
| pre_get_posts | Allows changing a WP_Query query before it runs. |
| request | Filters the parameters (variables) of the main WordPress query. |
Posts (pages attachments)
| attachment_fields_to_save | Saves a custom field added to an image (attachment) using the attachment_fields_to_edit hook. |
| before_delete_post | Fires before a post is deleted, at the very beginning of wp_delete_post(). |
| delete_post | Fires before a post (of any post type) is deleted from the database. |
| edit_post | Fires only when an existing post is updated. |
| post_class | Allows you to change the list of CSS classes for the current post. |
| post_updated | Fires after an existing post is updated. |
| publish_post | Fires when a post (a post of the post type) is published or updated, allowing an action to be performed. |
| register_post_type_args | Allows changing the arguments passed to register_post_type when any post type is registered. It fires before the default arguments are generated, merged with the supplied arguments, and applied. |
| sanitize_title | Allows changing a string passed to sanitize_title() after unwanted characters have been removed. |
| save_post | Fires whenever a post or page is created or updated, including publication through import, XML-RPC, or email. |
| save_post_(post_type) | Fires whenever a post of the specified type (post, page) is created or updated, including when it is published through import, XML-RPC, or email. |
| the_content_feed | Filters the full description content output in a feed. The feed type is passed in the second parameter. |
| the_excerpt | Filters the content of the post's “Excerpt” field before it is displayed. Used in |
| the_excerpt_rss | Called by the the_excerpt_rss() function, which outputs a short description in an RSS feed. Passes the short description text so it can be changed. |
| the_title | Applies to the post title, before retrieving or displaying it. |
| use_block_editor_for_post | Allows you to enable or disable Gutenberg (the WordPress block editor) for an individual post. |
| use_block_editor_for_post_type | Allows you to enable/disable content editing through Gutenberg (the WordPress block editor) for a post type. |
Users
| auth_cookie_expiration | Allows you to change the lifetime of cookies used to authenticate users. |
| author_link | Allows you to change the URL of an author's archive page. |
| editable_roles | Allows you to change the list of site user roles requested by get_editable_roles(). |
| map_meta_cap | Allows changing the primitive capabilities required when checking a user's permissions. |
| post_types_to_delete_with_user | Allows you to change the list of post types to delete when a user is deleted. This applies only to posts created by the user. |
| the_author_posts_link | Allows you to change the HTML of the link to the author's post archive page. |
| user_contactmethods | Allows you to change a user's additional contact information. |
| user_has_cap | Allows you to remove or add capabilities for an individual user. |
| user_register | Fires immediately after a new user has been registered on the site and the user data has been added to the database. |
Terms (tags categories)
| created_(taxonomy) | Fires after a term (taxonomy item) is added. |
| edited_(taxonomy) | Fires after a term (category or other taxonomy item) has been updated and its cache cleared. |
| get_terms_orderby | Filters the part of the SQL query responsible for the sorting column in get_terms(), get_categories(), wp_list_categories(). |
| pre_insert_term | Allows you to change a term name (category or tag) before it is sanitized and inserted into the database. |
| register_taxonomy_args | Allows you to change the arguments specified when registering a taxonomy. |
| single_cat_title | Allows you to change the title of a category archive page. |
| taxonomy_labels_(taxonomy) | Allows you to change the labels (headings) of a specified taxonomy, such as categories or tags. |
| term_updated_messages | Allows you to change messages displayed when terms (categories, tags, and so on) are handled on their creation and editing pages. |
| update_post_term_count_statuses | Allows you to change the list of post statuses included when updating taxonomy term counts. |
Media-data
| embed_oembed_html | Allows you to change cached oEmbed HTML when it is displayed. |
| getimagesize_mimes_to_exts | Allows you to add an image MIME type and its corresponding file extension. |
| manage_media_columns | Allows you to change the list of registered columns in the Media table. |
| oembed_dataparse | Allows you to change the content (HTML) generated when URLs supported by WordPress's oEmbed format are embedded. The change occurs before caching. |
| upload_mimes | Allows adding/removing file types that can be uploaded to the site (file MIME types allowed for upload). |
Translations (i18n l10n)
| gettext | Allows you to change a translated string (text). |
| gettext_with_context | Allows you to change translated text whose translation is requested with a translation context by the |
| ngettext | Allows you to change a string translated by |
| override_load_textdomain | Allows you to override loading the translation |
Meta-data
| is_protected_meta | Allows you to add the names (keys) of meta-fields that should be considered protected/hidden. |