San Francisco, California - Twitter has unveiled a new tool that allows users to tweet to smaller groups of select people, and it's now available to all users for the first time.

Who's in your inner circle? Looks like Twitter wants to know.

A new feature called Twitter Circle has now rolled out to everyone on both the platform's Android and iOS apps and via web browsers.

It enables users to build a group of up to 150 followers to become part of their "circle." Then, Twitter users are able to choose on a tweet-by-tweet basis whether to post something publicly, or just to their circle.

Twitter has been testing the feature since May and said the response has been "overwhelmingly positive," with users using Circle tweeting more often and receiving increased engagement in the form of more likes and replies.

"With Twitter Circle, people now have the flexibility to choose who can see and engage with their content on a tweet-by-tweet basis," the company said in a blog post.

"This makes it easier to have more intimate conversations and build closer connections with select followers."

The new addition is reminiscent of the Close Friends option on Instagram Stories, where IG users have the choice to post stories seen only by a curated list.

"We want to ensure everyone on Twitter has the choice, control, tools, and transparency to join the conversation how and when they want, and Twitter Circle is another important step in that direction," the company continued.

"Giving people the option to share thoughts with a select group of followers helps make tweeting more accessible," Twitter added. "This is true whether you're brand new to Twitter or you have millions of followers."