Now, when you reply to someone or a group, those @usernames won’t count toward your Tweet’s 140 characters.
Twitter is making some other simplifications along with this update:
● Who you are replying to will appear above the Tweet text rather than within the Tweet text itself, so you have more characters to have conversations.
● You can tap on “Replying to…” to easily see and control who’s part of your conversation.
● When reading a conversation, you’ll actually see what people are saying, rather than seeing lots of @usernames at the start of a Tweet.
The update is rolling out now on twitter.com as well as on Twitter for iOS and Android.