eSoftTools is the best and most efficient OST to PST Converter tool. This tool auto-detects and repairs corrupted Outlook OST file, allowing the user to access the files. It transforms the OST file into multiple formats such as HTML, PST, Outlook, EML, MSG, Office 365, MBOX, and vCard. This technique works for all versions of MS Outlook and Windows versions up to 10. For the conversion, installation of MS Outlook is not required. It can also offer a free demo pack to convert the first 25 items from each ost folder to pst or other required file formats in which they want to convert and check the performance of the tool to see how it works.
For more info- OST to PST Converter
For more info- OST to PST Converter