Vine has launched a new feature which allows users to send private video and text messages to each other.

Direct messaging is a major addition to the app, which is owned and developed by Twitter. Previously, users could only upload public videos or like, comment, and re-vine other people’s videos.

The move will allow Vine to compete with established private messaging services such as Snapchat and WhatsApp much more effectively, alongside more direct competitors such as Instagram. Owned by Facebook, Instagram launched its direct messaging service in December, 2013. This new addition to Vine also puts the popular app in a favorable position to defend against newcomers in the industry such as Blab; a new service from the makers of the social network Bebo, which launched just hours before Vine made their announcement.

The new feature allows users to record a video message, add a description or other text, and send it to anyone in their Vine network. Uniquely, it also allows users to send private messages to friends in your phone’s address book whether they have the vine app or not. Users without Vine will receive a link to your private video via SMS or E-Mail. 

You can also send messages to multiple users at once, which creates multiple 1-on-1 threads with you and people in your network, as explained in their blog post announcing the new feature.

The private messaging feature is currently open, allowing users to send and receive messages to/from anyone else that uses the Vine app. However, to combat spam users are required to verify their phone number before they can to send private messages to anyone that doesn’t already follow them. Messages from users you don’t follow appear in a separate inbox, much like Facebook’s messaging system, and you can reject all messages from people you don’t follow with one tap of the screen.

Online measurement company comScore reports that Vine is the fastest-growing ‘mobile-first’ social network. Having overtaken Snapchat in terms of monthly unique visitors just four months after it launched, Vine currently serves over 20,000,000 unique users every month. However, Instagram remains the leader in this space, with almost 70 million unique visitors in the U.S. alone.