Show IDs is the most comprehensive solution for determining IDs for posts, pages, and others!
Just activate the plugin and you'll be able to see IDs for everything.
Show IDs adds a new column to the All Posts admin table with the post ID.
Show IDs isn't limited to just posts. See pages and custom post types as well!
Need to see taxonomy IDs? Show IDs handles categories, tags, and custom taxonomies.
Show IDs is the most robust WordPress plugin for showing IDs of any WordPress segment.