If you have a large OST file and want to split it into two or more OST files, you can easily do it. Use the OST File Splitter Tool to split OST files. It splits OST files on various bases, such as Size and Date. The software supports OST files from any Outlook versions, including Windows 11, 10, 8.1, 8, and older. It is compatible with all Windows versions. You can try the free demo version of the tool which allows users to convert 50 emails for free.