Twitter said on Wednesday that it’s testing fleets, as in fleeting thoughts, for users to post content that disappears after 24 hours. The idea is to give an outlet to users who are uncomfortable with typical tweeting, which some complain is too public and permanent.

Fleets don’t appear in Twitter’s main feed. Instead, users who want to see them must tap on someone’s profile image. Viewers can react to the fleets by clicking the a love, fire, or other buttons, which the original authors can see in direct messages sent to them. Additionally, fleets can’t be retweeted.

“We’re hoping that Fleets can help people share the fleeting thoughts that they would have been unlikely to Tweet,” Kayvon Beykpour, Twitter’s product lead, tweeted on Wednesday. “This is a substantial change to Twitter, so we’re excited to learn by testing it.”

The new feature, which is currently available only for Android and iOS users in Brazil, mimics the general idea behind Facebook Stories, Instagram Stories, and Snapchat. Ephemeral content has been a big hit on those services.

Twitter users have long clamored for changes, like an edit button, to fix typos and revise posts that risk being misinterpreted. And while Twitter CEO Jack Dorsey has suggested Twitter may overhaul its service to help users give old tweets more context, he has repeatedly said that he will not add an edit button.

Twitter’s announcement of fleets coincides with Facebook’s efforts to make more of its content ephemeral and private under the theory that users increasingly prefer to communicate within small groups rather than the public at large.

Twitter’s timeline for testing fleets beyond Brazil, if at all, is unclear. The company did not immediately respond to a request for comment.

In recent years, Twitter has been mined for past and sometimes regrettable comments by public figures and for long-forgotten political campaign promises. But it has also led to controversies that have negatively impacted people’s careers like when old homophobic tweets by actor Kevin Hart emerged that forced him to step down as host of last year’s Oscars. Similarly, Disney fired the writer and director of Guardians of the Galaxy, James Gunn, after a series of decade-old insensitive tweets about pedophilia and molestation resurfaced. Gunn was later reinstated to his job. 

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