The best way to convert multiple OST files to PST format is by using the WebbyAcad OST to PST Converter tool. This software is highly recommended due to its efficiency and user-friendly interface. It allows batch conversion, enabling users to convert multiple OST files simultaneously, saving time and effort. The tool ensures data integrity, maintaining the original structure and content of emails, contacts, and calendar items. Additionally, it offers selective conversion options and supports various Outlook versions, making it a versatile and reliable solution for converting OST to PST.