In a move likely to compete with chat applications such as WhatsApp and Facebook Messenger, Twitter has removed the 140-character limit from Direct Messages. In a blog post Twitter says that the change is "another big step towards making the private side of Twitter even more powerful and fun." Twitter is also notes that this is just for Direct Messages, tweets will remain at 140 characters.
Longer Direct Messages will start rolling out today across iOS, Android, TweetDeck, Twitter for Mac and Twitter.com. It will continue to roll out over the next few weeks. No word as of it when or if 3rd party apps will get access to this feature.