| is_404() | Checks whether the 404 error page is displayed (HTTP 404: page not found). Conditional tag. |
| is_admin() | Whether the current request is for an administrative interface page. |
| is_archive() | Conditional tag. Return true when any of the archive pages are shown (Year, Category, Author, Post Type archive...). |
| is_attachment() | Is the query for an existing attachment page? |
| is_author() | Is the query for an existing author archive page? |
| is_blog_admin() | Whether the current request is for a site's admininstrative interface. |
| is_category() | Conditional tag. Checks whether the category page is displayed or not. |
| is_comment_feed() | Is the query for a comments feed? |
| is_customize_preview() | Checks whether the site is being previewed in the WordPress Customizer (the visual theme settings page). Conditional tag. |
| is_date() | Determines whether the date archive page is displayed. Conditional tag. |
| is_day() | Determines whether a day archive page is shown (example.com/2009/08/05) — page with posts for a specific day. A conditional tag. |
| is_embed() | Is the query for an embedded post? |
| is_feed() | Is the query for a feed? |
| is_front_page() | Checks whether the main (home) page of the site is displayed. Conditional tag. |
| is_home() | The conditional tag that checks if the page with the last posts is displayed, usually it is the main page of the site or the blog homepage. |
| is_month() | Determines whether a monthly archive page is shown (example.com/2009/08) — page with posts for a specific month. A conditional tag. |
| is_network_admin() | Whether the current request is for the network administrative interface. |
| is_page() | Checks whether a "static page" is displaying. You can specify an ID, name, or page title to check a specific page. Conditional tag. |
| is_page_template() | Whether currently in a page template. |
| is_paged() | Checks whether the pagination page is displayed (page type /page/2, /page/3). Conditional tag. |
| is_post_type_archive() | Is the query for an existing post type archive page? |
| is_preview() | Is the query for a post or page preview? |
| is_robots() | Checks if this is a request to robots.txt file. A conditional tag. |
| is_search() | Works when the search results page is displayed. Conditional tag. |
| is_single() | Checks whether the post page of any post type except attachment and page is displayed. Conditional tag. |
| is_singular() | Checks whether the post page is viewed (post, page, attachment, any post type). Conditional Tag. |
| is_ssl() | Checks whether secure HTTPS (SSL) connection is used. A conditional tag. |
| is_tag() | Is the query for an existing tag archive page? |
| is_tax() | Works on the custom taxonomy archive page. Conditional tag. |
| is_time() | Determines whether the query is for a time-based archive page (page of posts for the specified time). A conditional tag. |
| is_trackback() | Is the query for a trackback endpoint call? |
| is_user_admin() | Whether the current request is for a user admin screen. |
| is_year() | Determines whether a year archive page is shown (example.com/2009) — page with posts for a specific year. A conditional tag. |
| wp_doing_ajax() | Determines whether the current request is a WordPress Ajax request. |
| wp_doing_cron() | Determines whether the current request is a WordPress cron request. |