Like any other hex editor, FlexHEX lets you view and edit files residing on local devices or network shares. Unlike other hex editors, FlexHEX provides full support for NTFS files, which are based on a more complex model than customary FAT files. Specifically, FlexHEX supports alternate file streams and sparse files.

Although FlexHEX can edit files up to 8 exabytes long, most file systems don't allow files that large. The following are the file size limits for most widely used PC file systems:

File System Size Limit
FAT16 2 gigabytes (2,147,483,647 bytes)
FAT32 4 gigabytes (4,294,967,295 bytes)
NTFS 16 terabytes (17,592,185,978,880 bytes)
Max. Supported 8 exabytes (9,223,372,036,854,775,807 bytes)

You can set the desired size limit using the Tools/Settings menu command. By default FlexHEX limits the file size to 16 terabytes, that is the NTFS maximum file size.