Facebook is continuing its full-on assault on Snapchat by adding a Snapchat Stories clone to Facebook Messenger. Called Messenger Day, he new feature allows users to share photos with their contacts that disappear after 24 hours.

Messenger Day comes complete with effects and stickers, and users can decide to share their daily story with either a subset of their Messenger contacts, or everyone who is connected with them on the messaging platform. New stories automatically show up on top of the Messenger contact list, and users are also notified if someone who they are chatting with has added anything new to their story.

Facebook had been testing Messenger Day with a subset of its users in countries like Poland and Australia since last fall, and the company said Thursday that the feature had already been used by “millions of people around the world.” Now, it is making Messenger Day available to all of Messenger’s users via updates to the service’s iOS and Android apps.

The launch of Messenger Day is just Facebook’s latest in a long list of attempts to undermine Snapchat and its Snapchat Stories feature. Facebook-owned Instagram added Stories to its app in August. In January, Facebook began tests of the photo sharing format in its main app. And just last month, Facebook-owned Whatsapp added an encrypted version dubbed Status.

There’s a possibility that by commoditizing Stories, Facebook robs itself of the opportunity to build out a single platform that could compete against Snapchat. But the company seems to believe that services like Messenger, Whatsapp and Instagram all have their own distinctive user bases, and that a full-on assault will harm Snapchat more than a targeted approach.