Facebook today officially announced its photo sync feature that uploads and stores a user’s mobile photos in a private album on the social network for quick sharing later.

The company began testing photo sync for Android in September and earlier this month on iOS. Today it rolls out more widely with prompts at the top of mobile feed that ask users to opt in.

After users do so, they will be able to store 2 GB of photos that they can access from a private album on the web or decide to share with friends. So as not to consume a user’s data plan, Facebook will sync photos at a smaller file size if users are on a cellular network. When users are on Wi-Fi, which does not cut into a user’s data plan, Facebook will sync larger versions of photos. Users have the choice to sync over Wi-Fi only if they wish. Facebook will alert users with a notification when new photos have synced.

So far Facebook hasn’t positioned the feature as an alternative to Dropbox or other cloud hosting services, but it could end up serving a similar purpose for the masses looking to back up their photos. The company could eventually charge users who want more storage, but it might be more valuable for it to offer the service for free. Not only because another company could easily undercut the social network’s price, but together with Instagram, Facebook is positioning itself as “the place” for the world’s photos. And as TechCrunch points out, Facebook can collect data such as a user’s location through unpublished photos, which could ultimately help it target ads or offer other personalization.

Google has had a similar option called “Instant Upload” for Android and Google+ since it launched its own social network in 2011. It offers unlimited storage.