Before this change, users would simply reply to their previous tweet to create a thread. Now, once you have composed a tweet and used all your characters, you will see a “+” button in the composer to add another tweet in order to create a thread. From what I can tell, there’s no limit to how many tweets you can have when creating a thread. This means, God help us all.
We’ve made it easy to create a thread by adding a plus button in the composer, so you can connect your thoughts and publish your threaded Tweets all at the same time. You can continue adding more Tweets to your published thread at any time with the new “Add another Tweet” button. Additionally, it’s now simpler to spot a thread – we’ve added an obvious “Show this thread” label.
Twitter says this change is rolling out to all platforms over the coming weeks.