Facebook is rolling out a new tool that lets users find out why they're seeing certain posts on their News Feed.

The new feature, called "Why am I seeing this post?", essentially does what it says on the tin, showing a user the reasoning behind Facebook's ranking of posts from friends, pages and groups on their timeline.

"This is the first time that we've built information on how ranking works directly into the app," Ramya Sethuraman, product manager at Facebook, said in a blog post explaining the new tool.

The new button can be found in the drop down menu on the right hand corner of a post. Once clicked on, it will expand to show a user how the post has been tailored specifically to them.

That includes information on how often they interact with that post's author, how often they interact with the post's medium — whether it be videos, photos or links — and the popularity of the post compared to others.