OST (Offline Storage Table) and PST (Personal Storage Table) are two different file formats used by Microsoft Outlook to store emails, contacts, calendars, and other items. An OST file is created when you use Outlook in Cached Exchange Mode, while a PST file is a personal data file that is used to store data in Outlook.

If you need to OST to PST Converter, there are several tools available online that can help you accomplish this task. Some of the popular OST to PST converters include:

1. Stellar Converter for OST: It is a powerful tool that can convert OST files to PST and other file formats, such as MSG, EML, HTML, RTF, and PDF. The software supports all versions of MS Outlook and can handle large OST files.

2. Kernel for OST to PST: This is another popular tool for converting OST files to PST. It can also recover data from corrupt OST files and save it in PST, MSG, EML, PDF, HTML, and RTF formats.

3. SysTools OST to PST Converter: This tool can convert OST files to PST and other formats, such as MSG, EML, HTML, and PDF. It can also recover deleted emails and other items from OST files.

4. Aryson OST to PST Converter: This tool can convert OST files to PST and other formats, such as MSG, EML, PDF, and HTML. It supports all versions of MS Outlook and can handle large OST files.