Create ISO’s in OS X

To create an ISO image in OS X, use Disk Utility to burn a new image choosing “CD/DVD Master” as the Image Format. That creates an image with the cdr extension. Just rename the cdr file extension to iso and there you have it!

If you already have a DMG and want to convert it to an ISO, you can use hdiutil to do so:

hdiutil convert discimage.dmg -format UDTO -o output.iso

11 Comments

Will StitesOctober 25th, 2006 at 11:00 pm

Thanks for this post. It was just what I needed.

Will

c3oNovember 25th, 2006 at 1:37 am

Same here. Cheers :)

ooglekFebruary 15th, 2007 at 10:45 pm

Rock on mate! I can’t believe it isn’t documented on Apple’s support site.

One note, you have to select the first slice of the CD (not the drive itself) in order to be offered the CD/DVD Master Image format option.

circuitfiveJuly 14th, 2007 at 6:51 am

Worked great for me, to be a little more specific…

- put the CD or DVD into the drive – open Disk Utility (Applications -> Utilities) – select the the disk (NOT the media) (the smaller, subordinate item) on the left side of the Disk Utility interface – select File -> New -> Disk Image From… (it should show you the name of the disk you have selected) – choose a filename – choose “CD/DVD master” from the “image format” drop down – click save – after the .cdr file is created, change the .cdr extension to .iso – crack a beer, you’re done

cpSeptember 17th, 2007 at 11:18 am

circuitfive’s comments really clarified things. worked great!

anonSeptember 26th, 2007 at 8:24 pm

yeah i almost forgot the beer

reneOctober 29th, 2007 at 2:11 am

hey, thanx. got the cdr already.
just rename it?
excellent!!!

nnccApril 29th, 2009 at 10:27 pm

Perfect tip, man. Thanks.

Jon GeeDecember 15th, 2009 at 1:22 am

Thanks alot, a great time saver as VMWARE needs .iso images to install.

:-)

JacobJanuary 13th, 2010 at 10:11 pm

Excellent, Thanks very much for this!

c.thomasJuly 23rd, 2010 at 11:51 pm

In some cases, you may need to use

hdiutil makehybrid -iso -o yourdmg.dmg output.iso

This gives pretty good compatibility. It was necessary to create an ISO usable by Sun’s VirtualBox.

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