Utilize OST Converter to convert multiple Outlook OST files to PST online along with all type of data including mails, contacts, calendars, tasks, notes, briefcase, formatting, and attachments in an accurate form without misplacing any detail. Every user can easily understand how to change Outlook OST to PST in batch mode at once on any Windows Operating Systems i.e. Windows 11, 10, 8.1, 8, 7, XP, Vista, etc. First, try its free demo edition, which allows you to convert 25 items from OST folder to PST file including attachments without any charges. To bulk convert items from OST to PST online at once, then you need to buy license edition of the software.