Dropbox keeps snapshots of all changes made to files in your Dropbox account within your version history.
Not using Dropbox yet? See how Dropbox helps makes it easy to manage your document version history.
Dropbox Basic and Plus accounts can recover versions of a file made within the last 30 days.
Dropbox Professional and Business accounts can recover versions of a file made within the last 180 days.
Your restored file will be immediately available on dropbox.com and will be available on the desktop app the moment it completes syncing.