After testing the option with selected users over the past few weeks, Threads has now officially announced a broader launch of its new topic-based communities, which will provide another way for Threads users to find relevant discussions and like-interested people in the app.

As you can see in these examples, Threads communities will enable members to find topic-relevant discussions in a dedicated space, similar to the same on X, while posts submitted to any community that you’re a part of will be displayed in your “For You” feed with a tag signifying that it was posted into that group.
And given their popularity on X (X reported last year that time spent in communities had grown 600% year-over-year), and the rising interest in less public chatter, communities could be a good addition, helping to drive more interaction in the app.
As explained by Threads:
“As Threads has grown, we’ve seen people come together to develop and share their passions and expertise. With communities, it’s now even easier to find and connect with your people - and stay up-to-date on conversations you care about.”
Threads says that there are now over 100 communities that you can join in the app, based on trending topics:

Meta says that you can find relevant communities to join by searching for them by name, or by tapping on a community tag on a post in your feed.
“A three-dot icon on a topic tag indicates that it has a dedicated community. To join, tap Join in the top right.”
Membership to communities is public, and any community that you join will automatically be pinned in your feeds menu (accessible by swiping right from the main feed in the app) and tagged on your profile, “so people can see what you’re all about.”

Also, a small thing: Each group also has its own custom like emoji (like a basketball for “NBA Threads”), to provide an extra sense of presence.

Meta also says that soon, it’ll be adding special badges for standout community contributors.
“These individuals are among the most active and engaged users on the app and have helped establish communities around the most popular discussion topics. We’re also working on ranking within communities and the For You feed so that you see the most relevant posts first.”
So very similar to other communities and group engagement options, providing another way for Threads users to connect around topics of interest.
That could help to make Threads a more valuable platform for these groups, while also helping the Threads team with more algorithmic signals of user interests.
It’s a fairly logical addition, and it’ll be interesting to see which of these groups take off in the app, and become more relevant spaces for discussion among these topics.
Because with over 400 million users, some of them will catch on, and that could enable Threads to take another bite out of X, which still has a lot of embedded communities that are welded to the app.
Moving them, and changing habitual behaviors, will be difficult. But this is another step in that direction.