How to convert IMG files to ISO

IMG and ISO files are two common disc image file formats. They are often used to store, distribute or back up the content and file system of optical discs (CDs, DVDs and Blu-ray Discs) to another disc or device.

Despite having many similarities and practical use, ISO is widely accepted as a standard / format for disc images. ISO files are compatible with almost all operating systems (OS) and disc burning software. Many devices and operating systems have built-in tools that can extract and read disc files in ISO formats.

IMG files, on the other hand, are commonly compressed and therefore unreadable by some devices and disc imaging software. Due to this disparity in acceptance and compatibility, many users prefer to have disc images / files in ISO format.

If you find yourself needing to convert a disk image file from .img to.iso format, the conversion tools and methods in this post will come in handy. They are relevant for both Windows and Mac devices.

1. Rename the file extension

IMG and ISO disk image files have identical data structures, except that the former can be compressed while the latter cannot. If an IMG file is uncompressed, you can easily convert it to ISO by renaming the file extension. The content of the image file will work correctly and will remain unchanged.

Right click on the IMG file and select Rename in the context menu. Change the format (after the dot symbol) from .img to.iso and press Enter on the keyboard.

Open the renamed file and check if your computer can mount the ISO file. If you get an error message saying “The disk image file is damaged”, it is very likely that the IMG file is compressed. Restore the file extension to.img and use the other methods below to convert to ISO.

Quick tip: If you can’t change the file extension because the IMG file doesn’t have an .img extension suffix attached to its name, here’s how to make Windows show the file extension.

Launch File Explorer and go to the tab View. Next, select Options on the quick access toolbar.

In the Folder Options window, go to the tab View and uncheck the option Hide extensions for known file types. Select Apply and then OK. The IMG file you want to convert should now carry a suffix.img in the file name.

2. Use third party software

There are a lot of file management tools that offer file conversion services and they do it brilliantly. We have tested some of these programs and these are our favorites.

1. PowerISO

This tool allows you to convert around 30 different image file formats to ISO. Although the file conversion speed depends on the file size, PowerISO quickly converted our sample IMG file to ISO.

It is important to note that PowerISO works on a freemium model. The free version does the job at the same speed as the paid / registered version, but with some limitations. First, you can’t create, edit, or convert files larger than 300MB as a free user. Secondly, there is a 5 second pop-up (urging you to pay for the app) that you need to see every time you start the app.

Download PowerISO from the developer’s website and install it on your PC. Select Instruments from the menu bar and choose Convert file format.

Select the folder icon next to the dialog box Source file to choose the IMG file, check the box Enable password protection if you want to protect the resulting ISO file with a password and do click its OK to start the conversion.

2. MagicISO

This is another great tool for converting IMG files to ISO. It can convert files up to 10GB (in ISO format) in a single operation, but the free version has a limitation of 300MB. Unlike PowerISO, you don’t get annoying pop-ups when launching the app or anytime while using it.

Install and launch the app on your PC, then proceed to select Instruments on the menu bar and choose Converted.

Click the folder icon next to Choose source file and select the IMG file you want to convert. Verify that the output format is set to Standard ISO Image File (.ISO) and click Converted.

Convert IMG to ISO on Mac

The apps mentioned above are only compatible with Windows PC. If you are using a MacBook or iMac, there is an easy way to convert IMG to ISO without installing third party software. All you need is the Terminal app.

1. Go up Applications > Utility and start the application Terminal.

2. Type or paste hdiutil convert and leave a space.

3. Drag the IMG file you want to convert to the terminal console. Press the spacebar to leave a space and proceed to the next step.

4. Type or paste -format UDTO -o in the console and press the space bar.

5. Again, drag the IMG file you want to convert to Terminal, but this time rename the file extension from .img to.iso. You should have a command string like the one below.

hdiutil convert /Users/name/folder/File.img -format UDTO -o /Users/name/folder/File.iso

6. Finally, press Enter to execute the command.

The terminal will create a new copy of the file in CDR format (i.e.iso.cdr ) in the same path as the original IMG file.

CDR is the Mac variant of an ISO disc image file. Rename the file you just generated (remove the .cdr extension from the file name) and press Enter.

Select Usa.iso in the confirmation request.

That’s all; you have successfully converted the IMG file to ISO. You can also use this trick to convert DMG files to ISO.

IMG to ISO in the blink of an eye

These are the methods and utilities you can use to reliably convert IMG files to ISO. If you are a Windows user, third party software is your best bet. Alternatively, transfer the IMG file to an external storage device and convert it for free on a Mac with no size limit. Leave a comment if you are stuck, need further assistance, or have other equally effective methods.