I would imagine using a Disk Utility partition, but I didn't see the option in Disk Utility to split a larger partition into several.

How can it be done on a Mac?

I am doing this because I would like to Mail Drop the file.

2 Answers 2


OS X includes a command line tool called split. See man split or https://ss64.com/osx/split.html for all the details.

You can call split using the Terminal.app and the command:

split -b 5000m MYBIGFILE

To combine it again, have the receiver store all parts in a dedicated folder, open Terminal there and run

cat x?? > MYBIGFILE

(This assumes that you used the default output names when running split.)

  • Will this work with an encrypted .dmg file?
    – Baumr
    Commented Dec 6, 2015 at 16:19
  • 5
    It will work with anything, the splitting doesn't care about the data getting split.
    – nohillside
    Commented Dec 6, 2015 at 19:27
  • cat x* > MYBIGFILE will be better. * means that can be any character or symbol.
    – Zgpeace
    Commented Feb 14, 2020 at 0:34
  • 1
    Just don't have any files with an "x" at the beginning if you plan to do this.
    – turiyag
    Commented Dec 1, 2020 at 22:18

I simply use the free software Data Tape 3. Why tampering with the fidgety Terminal?

  • 4
    "Fidgety" ? The split command is time-tested and extremely well documented. And easy as heck.
    – Br.Bill
    Commented Oct 15, 2021 at 19:22
  • 2
    It would be much more helpful if you also explained when and how using the split command & Terminal might create problems, if any, contrary to the general view.
    – Alper
    Commented Oct 15, 2021 at 22:52

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .