Title: Functions | Page 39 of 49 | Developer.WordPress.org --- # Functions * function[is_site_admin()](https://developer.wordpress.org/reference/functions/is_site_admin/) * Determine if user is a site admin. * Used by [0 functions](https://developer.wordpress.org/reference/functions/is_site_admin/#used-by) | Uses [4 functions](https://developer.wordpress.org/reference/functions/is_site_admin/#uses) | Source: [wp-includes/ms-deprecated.php:64](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/ms-deprecated.php#L64-L79) * function[is_site_meta_supported()](https://developer.wordpress.org/reference/functions/is_site_meta_supported/) * Determines whether site meta is enabled. * Used by [4 functions](https://developer.wordpress.org/reference/functions/is_site_meta_supported/#used-by) | Uses [5 functions](https://developer.wordpress.org/reference/functions/is_site_meta_supported/#uses) | Source: [wp-includes/functions.php:6520](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/functions.php#L6520-L6537) * function[is_ssl()](https://developer.wordpress.org/reference/functions/is_ssl/) * Determines if SSL is used. * Used by [25 functions](https://developer.wordpress.org/reference/functions/is_ssl/#used-by) | Uses [0 functions](https://developer.wordpress.org/reference/functions/is_ssl/#uses) | Source: [wp-includes/load.php:1659](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/load.php#L1659-L1673) * function[is_sticky()](https://developer.wordpress.org/reference/functions/is_sticky/) * Determines whether a post is sticky. * Used by [11 functions](https://developer.wordpress.org/reference/functions/is_sticky/#used-by) | Uses [4 functions](https://developer.wordpress.org/reference/functions/is_sticky/#uses) | Source: [wp-includes/post.php:2877](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/post.php#L2877-L2902) * function[is_subdomain_install()](https://developer.wordpress.org/reference/functions/is_subdomain_install/) * Whether a subdomain configuration is enabled. * Used by [15 functions](https://developer.wordpress.org/reference/functions/is_subdomain_install/#used-by) | Uses [0 functions](https://developer.wordpress.org/reference/functions/is_subdomain_install/#uses) | Source: [wp-includes/ms-load.php:18](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/ms-load.php#L18-L24) * function[is_success()](https://developer.wordpress.org/reference/functions/is_success/) * Used by [1 function](https://developer.wordpress.org/reference/functions/is_success/#used-by) | Uses [0 functions](https://developer.wordpress.org/reference/functions/is_success/#uses) | Source: [wp-includes/rss.php:698](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/rss.php#L698-L700) * function[is_super_admin()](https://developer.wordpress.org/reference/functions/is_super_admin/) * Determines whether user is a site admin. * Used by [7 functions](https://developer.wordpress.org/reference/functions/is_super_admin/#used-by) | Uses [4 functions](https://developer.wordpress.org/reference/functions/is_super_admin/#uses) | Source: [wp-includes/capabilities.php:1181](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/capabilities.php#L1181-L1202) * function[is_tag()](https://developer.wordpress.org/reference/functions/is_tag/) * Determines whether the query is for an existing tag archive page. * Used by [11 functions](https://developer.wordpress.org/reference/functions/is_tag/#used-by) | Uses [3 functions](https://developer.wordpress.org/reference/functions/is_tag/#uses) | Source: [wp-includes/query.php:300](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/query.php#L300-L309) * function[is_tax()](https://developer.wordpress.org/reference/functions/is_tax/) * Determines whether the query is for an existing custom taxonomy archive page. * Used by [11 functions](https://developer.wordpress.org/reference/functions/is_tax/#used-by) | Uses [3 functions](https://developer.wordpress.org/reference/functions/is_tax/#uses) | Source: [wp-includes/query.php:337](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/query.php#L337-L346) * function[is_taxonomy()](https://developer.wordpress.org/reference/functions/is_taxonomy/) * Checks that the taxonomy name exists. * Used by [0 functions](https://developer.wordpress.org/reference/functions/is_taxonomy/#used-by) | Uses [2 functions](https://developer.wordpress.org/reference/functions/is_taxonomy/#uses) | Source: [wp-includes/deprecated.php:2502](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/deprecated.php#L2502-L2505) * function[is_taxonomy_hierarchical()](https://developer.wordpress.org/reference/functions/is_taxonomy_hierarchical/) * Determines whether the taxonomy object is hierarchical. * Used by [26 functions](https://developer.wordpress.org/reference/functions/is_taxonomy_hierarchical/#used-by) | Uses [2 functions](https://developer.wordpress.org/reference/functions/is_taxonomy_hierarchical/#uses) | Source: [wp-includes/taxonomy.php:399](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/taxonomy.php#L399-L406) * function[is_taxonomy_viewable()](https://developer.wordpress.org/reference/functions/is_taxonomy_viewable/) * Determines whether a taxonomy is considered “viewable”. * Used by [2 functions](https://developer.wordpress.org/reference/functions/is_taxonomy_viewable/#used-by) | Uses [1 function](https://developer.wordpress.org/reference/functions/is_taxonomy_viewable/#uses) | Source: [wp-includes/taxonomy.php:5101](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/taxonomy.php#L5101-L5110) * function[is_term()](https://developer.wordpress.org/reference/functions/is_term/) * Check if Term exists. * Used by [0 functions](https://developer.wordpress.org/reference/functions/is_term/#used-by) | Uses [2 functions](https://developer.wordpress.org/reference/functions/is_term/#uses) | Source: [wp-includes/deprecated.php:2519](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/deprecated.php#L2519-L2522) * function[is_term_publicly_viewable()](https://developer.wordpress.org/reference/functions/is_term_publicly_viewable/) * Determines whether a term is publicly viewable. * Used by [2 functions](https://developer.wordpress.org/reference/functions/is_term_publicly_viewable/#used-by) | Uses [2 functions](https://developer.wordpress.org/reference/functions/is_term_publicly_viewable/#uses) | Source: [wp-includes/taxonomy.php:5122](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/taxonomy.php#L5122-L5130) * function[is_textdomain_loaded()](https://developer.wordpress.org/reference/functions/is_textdomain_loaded/) * Determines whether there are translations for the text domain. * Used by [2 functions](https://developer.wordpress.org/reference/functions/is_textdomain_loaded/#used-by) | Uses [0 functions](https://developer.wordpress.org/reference/functions/is_textdomain_loaded/#uses) | Source: [wp-includes/l10n.php:1443](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/l10n.php#L1443-L1446) * function[is_theme_paused()](https://developer.wordpress.org/reference/functions/is_theme_paused/) * Determines whether a theme is technically active but was paused while loading. * Used by [0 functions](https://developer.wordpress.org/reference/functions/is_theme_paused/#used-by) | Uses [2 functions](https://developer.wordpress.org/reference/functions/is_theme_paused/#uses) | Source: [wp-admin/includes/theme.php:1117](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-admin/includes/theme.php#L1117-L1127) * function[is_time()](https://developer.wordpress.org/reference/functions/is_time/) * Determines whether the query is for a specific time. * Used by [0 functions](https://developer.wordpress.org/reference/functions/is_time/#used-by) | Uses [3 functions](https://developer.wordpress.org/reference/functions/is_time/#uses) | Source: [wp-includes/query.php:786](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/query.php#L786-L795) * function[is_trackback()](https://developer.wordpress.org/reference/functions/is_trackback/) * Determines whether the query is for a trackback endpoint call. * Used by [2 functions](https://developer.wordpress.org/reference/functions/is_trackback/#used-by) | Uses [3 functions](https://developer.wordpress.org/reference/functions/is_trackback/#uses) | Source: [wp-includes/query.php:810](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/query.php#L810-L819) * function[is_uninstallable_plugin()](https://developer.wordpress.org/reference/functions/is_uninstallable_plugin/) * Determines whether the plugin can be uninstalled. * Used by [2 functions](https://developer.wordpress.org/reference/functions/is_uninstallable_plugin/#used-by) | Uses [2 functions](https://developer.wordpress.org/reference/functions/is_uninstallable_plugin/#uses) | Source: [wp-admin/includes/plugin.php:1280](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-admin/includes/plugin.php#L1280-L1289) * function[is_upload_space_available()](https://developer.wordpress.org/reference/functions/is_upload_space_available/) * Determines if there is any upload space left in the current blog’s quota. * Used by [4 functions](https://developer.wordpress.org/reference/functions/is_upload_space_available/#used-by) | Uses [2 functions](https://developer.wordpress.org/reference/functions/is_upload_space_available/#uses) | Source: [wp-includes/ms-functions.php:2667](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/ms-functions.php#L2667-L2673) * function[is_user_admin()](https://developer.wordpress.org/reference/functions/is_user_admin/) * Determines whether the current request is for a user admin screen. * Used by [6 functions](https://developer.wordpress.org/reference/functions/is_user_admin/#used-by) | Uses [0 functions](https://developer.wordpress.org/reference/functions/is_user_admin/#uses) | Source: [wp-includes/load.php:1431](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/load.php#L1431-L1439) * function[is_user_logged_in()](https://developer.wordpress.org/reference/functions/is_user_logged_in/) * Determines whether the current visitor is a logged in user. * Used by [52 functions](https://developer.wordpress.org/reference/functions/is_user_logged_in/#used-by) | Uses [1 function](https://developer.wordpress.org/reference/functions/is_user_logged_in/#uses) | Source: [wp-includes/pluggable.php:1258](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/pluggable.php#L1258-L1262) * function[is_user_member_of_blog()](https://developer.wordpress.org/reference/functions/is_user_member_of_blog/) * Finds out whether a user is a member of a given blog. * Used by [7 functions](https://developer.wordpress.org/reference/functions/is_user_member_of_blog/#used-by) | Uses [6 functions](https://developer.wordpress.org/reference/functions/is_user_member_of_blog/#uses) | Source: [wp-includes/user.php:1162](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/user.php#L1162-L1207) * function[is_user_option_local()](https://developer.wordpress.org/reference/functions/is_user_option_local/) * Check whether a usermeta key has to do with the current blog. * Used by [0 functions](https://developer.wordpress.org/reference/functions/is_user_option_local/#used-by) | Uses [4 functions](https://developer.wordpress.org/reference/functions/is_user_option_local/#uses) | Source: [wp-includes/ms-deprecated.php:543](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/ms-deprecated.php#L543-L555) * function[is_user_spammy()](https://developer.wordpress.org/reference/functions/is_user_spammy/) * Determines whether a user is marked as a spammer, based on user login. * Used by [2 functions](https://developer.wordpress.org/reference/functions/is_user_spammy/#used-by) | Uses [2 functions](https://developer.wordpress.org/reference/functions/is_user_spammy/#uses) | Source: [wp-includes/ms-functions.php:2348](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/ms-functions.php#L2348-L2358) * function[is_utf8_charset()](https://developer.wordpress.org/reference/functions/is_utf8_charset/) * Indicates if a given slug for a character set represents the UTF-8 text encoding. If not provided, examines the current blog’s charset. * Used by [3 functions](https://developer.wordpress.org/reference/functions/is_utf8_charset/#used-by) | Uses [1 function](https://developer.wordpress.org/reference/functions/is_utf8_charset/#uses) | Source: [wp-includes/functions.php:7587](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/functions.php#L7587-L7589) * function[is_wpmu_sitewide_plugin()](https://developer.wordpress.org/reference/functions/is_wpmu_sitewide_plugin/) * Deprecated functionality for determining if the current plugin is network-only. * Used by [0 functions](https://developer.wordpress.org/reference/functions/is_wpmu_sitewide_plugin/#used-by) | Uses [2 functions](https://developer.wordpress.org/reference/functions/is_wpmu_sitewide_plugin/#uses) | Source: [wp-admin/includes/ms-deprecated.php:78](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-admin/includes/ms-deprecated.php#L78-L81) * function[is_wp_error()](https://developer.wordpress.org/reference/functions/is_wp_error/) * Checks whether the given variable is a WordPress Error. * Used by [546 functions](https://developer.wordpress.org/reference/functions/is_wp_error/#used-by) | Uses [1 function](https://developer.wordpress.org/reference/functions/is_wp_error/#uses) | Source: [wp-includes/load.php:1802](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/load.php#L1802-L1817) * function[is_wp_version_compatible()](https://developer.wordpress.org/reference/functions/is_wp_version_compatible/) * Checks compatibility with the current WordPress version. * Used by [16 functions](https://developer.wordpress.org/reference/functions/is_wp_version_compatible/#used-by) | Uses [1 function](https://developer.wordpress.org/reference/functions/is_wp_version_compatible/#uses) | Source: [wp-includes/functions.php:8953](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/functions.php#L8953-L8976) * function[is_year()](https://developer.wordpress.org/reference/functions/is_year/) * Determines whether the query is for an existing year archive. * Used by [3 functions](https://developer.wordpress.org/reference/functions/is_year/#used-by) | Uses [3 functions](https://developer.wordpress.org/reference/functions/is_year/#uses) | Source: [wp-includes/query.php:834](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/query.php#L834-L843) [Previous Page](https://developer.wordpress.org/reference/functions/page/38/?output_format=md) [1](https://developer.wordpress.org/reference/functions/?output_format=md) … [37](https://developer.wordpress.org/reference/functions/page/37/?output_format=md) [38](https://developer.wordpress.org/reference/functions/page/38/?output_format=md) 39 [40](https://developer.wordpress.org/reference/functions/page/40/?output_format=md) [41](https://developer.wordpress.org/reference/functions/page/41/?output_format=md)… [49](https://developer.wordpress.org/reference/functions/page/49/?output_format=md) [Next Page](https://developer.wordpress.org/reference/functions/page/40/?output_format=md)