The best and most effective tool for converting an OST file into an Outlook PST file with 100% accuracy and no data loss is called OST to PST Converter. It is a versatile software that can convert OST files to PST files and other file types, including MBOX, PDF, and JSON. Additionally, the software is capable of exporting OST items—including emails, calendars, contacts, and tasks—into 15+ web- and cloud-based email applications.