Mounting ISO Images in Mac OS X Without Expensive Software

Last updated on April 28, 2016

I was speaking with a colleague today about ISO files/images in Mac OS X, and when he expressed his disappointment with existing software.
I said I would show him some cheap and easy ways to mount ISO files and how to backup any CDROM using Disk Utility.

Mounting an ISO on your Mac is accomplished using the hdiutil command.
To attach an image file,

1. you will first need to open up your Terminal.app
2.  type  hdiutil attach -readonly filename where filename is the full unix path of your file (just to be safe). When I was testing this my command looked like “hdiutil attach -readonly /Users/ck/Downloads/cdrom-1.33.iso”.
3. If you run into problems or find your image type says not supported, generally because it is a .cdr file, try hdiutil attach -imagekey diskimage-class=CRawDiskImage filename.

This should mount the image in your Finder sidebar as you would expect a normal CDROM would. If we are concerned with creating images with Disk Utility, that is as simple as dragging the inserted CD onto the Disk Utility application, or selecting it within Disk Utility and selecting New Image.