Twitter is taking a page from Reddit's playbook, by testing a new downvote and upvote reaction system for tweets.

"Some of you on iOS may see different options to up or down vote on replies. We're testing this to understand the types of replies you find relevant in a convo, so we can work on ways to show more of them", Twitter announced in a tweet on 21 July 2021. In another tweet, the company clarified it's a test for research right now and that your upvotes or downvotes won’t change the order of replies.

Keep in mind Reddit has long offered downvoting and upvoting, but its system is a way of ordering a subreddit’s replies, responses, and posts. Twitter, however, makes clear that its upvotes and downvotes work differently in the test. It said downvotes are not a dislike button and currently aren't public (they're only visible to you), but your upvotes on tweets will be shown to others as likes. 

Twitter is testing the feature among a small group of users on iOS. Those users may see different styles, too, such as up and down arrows, a heart icon and a down arrow, or thumbs up and thumbs down icons. It hasn't said whether it plans to make voting an official feature or how it'll affect your Twitter feed. 

It's worth noting Twitter has been extremely transparent in recent months about its upcoming plans, whether it's new features in the works or even that it's been considering subscription options. Just yesterday, it announced an overhaul to TweetDeck - something you can now test with a simple browser hack.