I have a Nero Disk Image(.nrg) File and I would like to mount it on OSX to copy it's contents. I've tried to rename to .iso and to use NRG2ISO with no luck.

Any tips ?

5 Answers 5


A little googling led me to this thread on MacRumors.com

It appears that if the ISO is a single session CD image you can just knock the first 600 bytes off with a terminal command and it'll be readable as an ISO (change file type to .iso after performing the command).

I'd recommend making a backup of the .nrg file before trying this though!

$ dd if=image.nrg of=cdrom.iso bs=512 skip=600

(↑ credit to balamw on macrumors forums)

Also, If you're just looking to extract pictures from the disk, File Juicer may also be worth a look!

  • Thank you for the tip, but this didn't work for me :( (when I mount the resulting iso I get 'not recognized') Commented Jul 28, 2011 at 14:30
  • 1
    dd just reads the in file (if) so it's not writing to the nrg file in this case.
    – bmike
    Commented Jul 28, 2011 at 16:54
  • bs=512 skip=600 skips the first 307,200 (512 x 600) bytes, not just 600.
    – user101978
    Commented Sep 9, 2019 at 22:02

Had the same experience as the OP. Tried using nrg2iso, tried renaming the file to .iso and also tried the dd command from that MacRumors thread. Nothing worked.

However, I then found nrg4iso which worked perfectly! The project has been abandoned since 2007 but it still works.

  • 1
    I tried nrg4iso, but it erred with the following message: "Source is a Nero DAO (Disc at once) image with 2 session(s)." Commented Jan 3, 2014 at 6:21

dd variant not work for me. So, i find another one with poweriso:


Use: ./poweriso convert ~/Desktop/image.nrg -o ~/Desktop/image.iso -ot iso


With .nrg images from audio CDs, the solutions proposed in the other answers do not work (e.g. failing with Source is a Nero DAO (Disk at once) with 1 session(s) ).

However, the commercial Deamon Tools are now available for Mac OSX. Using these, you can mount the .nrg as an Audio CD.


There are not many options on Mac for this purpose. I think AnyToISO is good freemium choice. Its freemium version supports up to 870 MB.

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