JK File Splitter

JK File Splitter is a tool that facilitates a straightforward interface and options for splitting large files into smaller chunks to be able to transfer them to other computers, as well as for merging back the segments to reconstruct the original items. In addition to custom segment size, it contains a few preset profiles optimized for various goals.

Preset and custom segment size

All options are visible in the control panel, giving you an overview. After selecting the file operation between trimming and merging, you can opt for a predefined size optimized for floppy disks (1.4MB), regular email size (2.8MB), good email size (5MB) or large files (10MB). Otherwise, it's possible to specify any other size to take into account for each smaller chunk (kilobytes).

Split files into multiple parts and merge them back together

Once the file is indicated with the aid of the file browser, the tool splits it into multiple parts and places them in the same directory as the source. They cannot be used independently, retain the name of the original file and apply numerical incrementation to keep track of them easier.
Furthermore, they have the .fss format, except for one, the main part, which has the .fsm extension. The difference between the two types is that the main file is requested by JK File Splitter when attempting to combine the pieces to rebuild the original data, since it identifies the remaining parts automatically. The only condition is that they must exist in the same directory.

Clear-cut, tiny and portable file splitter and merger

The source items do not get auto-deleted by the application when it comes to either splitting or merging jobs, so you don't have to worry about creating backups. Unfortunately, it doesn't integrate settings for setting a preferred saving directory for the two kinds of operations.
JK File Splitter is lightweight and wrapped in a portable package, which means that it can be launched from any directory on the PC as well as from a removable storage unit without setup. It's standalone, so it doesn't need DLLs or other components to work.

Outdated but without compatibility issues on newer Windows

By the look of the interface, the application hasn't received updates for a very long time. However, it was successful in the most recent version of Windows in our evaluation.
The main issue with the fact that it's outdated is that JK File Splitter has outdated predefined sizes, such as floppy disk. However, it was speedy in our tests and managed to split and join files without any problems.