How to Write ISO to USB on Mac

Writing an ISO file to a USB drive on a Mac computer can be a useful skill to have, especially if you need to create a bootable USB for installing a new operating system or for other purposes. It allows you to quickly and easily transfer files from your computer to a USB drive, making it accessible on other devices. In this blog post, we will explore different methods to write ISO to USB on Mac, providing you with step-by-step instructions and helpful tips along the way.

Video Tutorial:

Why You Need to Write ISO to USB

There are several reasons why you might need to write an ISO file to a USB drive on your Mac. Here are some of the most common scenarios:

1. Creating a Bootable USB: If you want to install a new operating system on your computer or perform a system recovery, you will need to create a bootable USB drive containing the necessary files.
2. Transferring Large Files: USB drives provide a convenient way to transfer large files between computers, and writing an ISO file to a USB drive allows you to easily transport and share large files with others.
3. Portable Storage: USB drives are compact and portable, making them an ideal choice for storing and carrying important files or data backups.
4. Software Installation: Some software applications are distributed as ISO files, and writing these files to a USB drive allows you to install the software on a computer that does not have an optical disc drive.

Now that we understand the importance of writing ISO files to USB on Mac, let’s explore different methods to accomplish this task.

Method 1: Using Disk Utility

Writing an ISO to USB using Disk Utility is a straightforward process. Here is a step-by-step guide to help you get started:

1. Connect the USB drive to your Mac.
2. Open "Disk Utility" from the "Applications" folder or by searching for it using Spotlight.
3. In Disk Utility, select the USB drive from the list of available drives on the left-hand side of the window.
4. Click on the "Erase" tab at the top of the window.
5. Choose a suitable format for the USB drive (e.g., "ExFAT" for compatibility with both Mac and Windows).
6. Enter a name for the USB drive.
7. Click on the "Erase" button to format the USB drive.
8. Once the USB drive is formatted, go to the "File" menu and select "Open Disk Image…"
9. Locate and select the ISO file you want to write to the USB drive.
10. Click on the "Open" button.
11. In the left-hand sidebar of Disk Utility, you will now see the ISO file listed. Drag it onto the USB drive listed on the sidebar as well.
12. Click on the "Restore" button in the toolbar.
13. A confirmation dialog will appear, asking if you want to erase the contents of the destination drive. Click on the "Erase" button to proceed.
14. Wait for the restoration process to complete. This may take some time depending on the size of the ISO file.

Pros:
– Disk Utility is a built-in tool on Mac, so no additional software installation is required.
– The process is relatively straightforward and can be completed by users of all skill levels.

Cons:
– The restoration process can be time-consuming, especially for large ISO files.
– Disk Utility may not be able to handle certain ISO files, leading to errors during the process.

Method 2: Using Terminal

If you prefer using the command-line interface, you can write an ISO file to USB on Mac using Terminal. Here are the steps:

1. Connect the USB drive to your Mac.
2. Open "Terminal" from the "Applications" folder or by searching for it using Spotlight.
3. Type the following command to list the available disks on your system:
"`
diskutil list
"`
4. Locate the identifier of the USB drive from the list. It usually looks like "/dev/diskX" (replace X with the appropriate number).
5. Ensure that there are no active partitions on the USB drive. If there are, use the following command to remove them (replace diskX with the appropriate identifier):
"`
diskutil partitionDisk /dev/diskX 1 MBRFormat "Untitled" 100%
"`
6. Once the USB drive is ready, use the following command to write the ISO file to the USB drive (replace diskX and /path/to/iso with the appropriate identifiers and file paths):
"`
sudo dd if=/path/to/iso of=/dev/diskX bs=1m
"`
7. Enter your administrator password when prompted and press Enter to start the process.
8. Wait for the ISO file to be written to the USB drive. This may take some time depending on the size of the ISO file.

Pros:
– Terminal provides more control and flexibility compared to Disk Utility.
– The process is relatively fast and efficient.

Cons:
– Using Terminal requires familiarity with command-line interface and commands.
– Accidental misuse of commands can result in data loss, so it’s important to double-check the commands before executing them.

Method 3: Using Third-Party Software

Another option to write ISO to USB on Mac is to use third-party software specifically designed for this purpose. One popular software is "Etcher." Follow these steps to use it:

1. Download and install "Etcher" from the official website (https://www.balena.io/etcher/).
2. Launch "Etcher" after installation.
3. Connect the USB drive to your Mac.
4. In the "Etcher" interface, click on the "Select Image" button and locate the ISO file you want to write to the USB drive.
5. Click on the "Select Drive" button and choose the USB drive from the list.
6. Verify that the correct ISO file and USB drive are selected, then click on the "Flash!" button to start the writing process.
7. Wait for "Etcher" to finish writing the ISO file to the USB drive. This process may take some time depending on the size of the ISO file.

Pros:
– Third-party software like "Etcher" often provides a user-friendly interface with guided steps.
– These software tools are specifically designed for writing ISO files to USB drives, offering better compatibility and reliability.

Cons:
– Third-party software may require additional installation and take up storage space on your Mac.
– Some third-party software options may require a paid license for full functionality.

Method 4: Via TransMac (for writing Windows ISO files on Mac)

If you need to write a Windows ISO file to a USB drive on your Mac, you can use TransMac. Follow these steps:

1. Download and install TransMac from the official website (https://www.acutesystems.com/scrtm.htm).
2. Launch TransMac after installation.
3. Connect the USB drive to your Mac.
4. In TransMac, right-click on the USB drive and select "Format Disk for Mac."
5. Right-click on the USB drive again and select "Restore with Disk Image."
6. Locate and select the Windows ISO file you want to write to the USB drive.
7. Click on the "OK" button to start the restoration process.
8. Wait for TransMac to finish writing the Windows ISO file to the USB drive. This may take some time depending on the size of the ISO file.

Pros:
– TransMac provides a specific solution for writing Windows ISO files on a Mac.
– The process is relatively straightforward and does not require complex commands.

Cons:
– TransMac is a paid software, and you need to purchase a license to use it beyond the trial period.
– It is limited to writing Windows ISO files only and may not work with other types of ISO files.

What to Do If You Can’t Write ISO to USB

If you are unable to write an ISO file to a USB drive on your Mac using the methods mentioned above, here are some possible fixes to consider:

1. Check USB Compatibility: Ensure that the USB drive is compatible with your Mac. Try using a different USB drive or port to rule out any hardware compatibility issues.
2. Verify ISO File: Make sure the ISO file is not corrupted or incomplete. Try redownloading the ISO file from a reliable source.
3. Update Software: Ensure that you are using the latest version of the software (e.g., Disk Utility, TransMac) for writing ISO files to USB drives. Check for any available updates and install them if necessary.
4. Use a Different Computer: If all else fails, try using a different computer (Mac or Windows) to write the ISO file to a USB drive. This can help determine if the issue is specific to your Mac or if there is a problem with the ISO file itself.

Bonus Tips

Here are three bonus tips to enhance your experience when writing ISO files to USB on a Mac:

1. Use High-Quality USB Drives: To ensure reliable performance and data integrity, choose USB drives from reputable brands known for their quality and durability.
2. Double-Check ISO Compatibility: Verify that the ISO file you want to write is compatible with the intended purpose. Some ISO files may be specific to certain operating systems or software applications.
3. Safely Eject USB Drives: Always remember to properly eject USB drives from your Mac before physically disconnecting them. This helps prevent data corruption and ensures that all pending write operations are completed.

5 FAQs

Q1: How do I know if the ISO file is bootable?

A: To determine if an ISO file is bootable, you can examine its contents. A bootable ISO will typically contain a specific file structure and bootable files necessary for the operating system or software application to start on a computer.

Q2: Can I write multiple ISO files to the same USB drive?

A: Yes, it is possible to write multiple ISO files to the same USB drive using partitioning tools or disk imaging software. However, keep in mind that each ISO file will require its own boot loader and bootable configuration, which may require extra setup steps.

Q3: Can I write ISO files to USB drives formatted with NTFS?

A: Yes, it is possible to write ISO files to USB drives formatted with NTFS. However, macOS can only read NTFS-formatted drives by default. To write files to an NTFS-formatted USB drive on Mac, you may need to install third-party drivers or use special software like Paragon NTFS.

Q4: Can I write ISO files to USB drives using a Windows PC?

A: Yes, you can write ISO files to USB drives using a Windows PC. The process typically involves using built-in tools like "Rufus" or third-party software like "Win32 Disk Imager." The steps may vary slightly depending on the specific software used.

Q5: Can I write ISO files to USB drives using a Linux-based computer?

A: Yes, you can write ISO files to USB drives using a Linux-based computer. Linux distributions often provide built-in tools like "dd" or "gnome-disks" for writing ISO files to USB drives. The steps may vary depending on the Linux distribution and the specific tool used.

Final Thoughts

Writing an ISO file to a USB drive on a Mac is an essential skill that allows you to create bootable USBs, transfer large files, and install software applications. In this blog post, we explored different methods for achieving this task, including using Disk Utility, Terminal, third-party software, and TransMac (for writing Windows ISO files). We also provided helpful tips for troubleshooting and maximizing your experience. Remember to follow the steps carefully and backup any important data before proceeding. With the right tools and techniques, you can easily write ISO files to USB drives on your Mac and unlock a world of possibilities.