Fix An Unreadable USB Flash Drive Without Data Loss On Mac

Summary: USB flash drives play an important role in storing and transferring files between different devices. But like other storage devices, you may find your USB flash drive unreadable on Mac. So in this article, we will introduce you to how to fix an unreadable USB flash drive on Mac. 


False connection, no file system, unsupported disk encryption, and information corruption are all possible to make your USB flash drive not readable. Sometimes, the entire USB flash drive is not showing up on Mac, and sometimes you can see it but can’t access files on the USB flash drive on Mac. Even you may receive an error message saying that the disk you inserted was not readable by this computer.

It’s hard to pinpoint the exact causes of this error, but we will troubleshoot the problem and tell you how to fix an unreadable USB flash drive on Mac effectively.

How to Fix an Unreadable USB Flash Drive on Mac?

Method 1: Check USB Port or Cable

Use another device with the cable and port you used with the unreadable USB device. If you find no problem with the cable and port, we can now focus on the drive itself.

Method 2: Format a New Drive

Most flash drives that you can purchase are preformatted in the Windows format because there are more PC users than Mac users. But in some cases, the drives were not formatted at all. If the USB flash drive was not formatted, then when you plug it into the Mac, you will see the error message The disk you inserted was not readable by this computer.

MAC-The disk you inserted was not readable by this computer

  1. If the drive was never used before, click on the Initialize… button. This will open Disk Utility.
  2. On the left side of the app, locate the USB flash drive.
  3. Click on the Partition button in the top toolbar.
  4. Then type in some basic information: Partition Name, Size and Format. Ignore the size and use the default.

    mac-disk utility-partition

When it comes to the format, there are many choices, and you can choose the optimum format depending on how the flash drive is going to be used. If the flash drive will only be used with Mac computers, then the best format is OS X Extended (Journaled). In case there is a possibility that the flash drive will be used with Windows computers, then pick ExFAT.

Method 3: Update USB Driver

An outdated USB device driver is one of the common reasons causing a USB flash drive not readable on Mac. Therefore, updating the driver, which will restore the normal interaction between your Mac and the USB flash drive.

To update the USB flash driver, you need to update the Mac operating system. Follow these steps to check if any update is available for your Mac:

  1. Click on the Apple icon and select Software Update…
  2. If Mac suggests a new macOS update, click Upgrade Now and follow its instruction to update it.Mac software Update
  3. If your Mac is up to date, you can visit the USB manufacturer’s official website to see if it offers any driver updates.

Method 4: Disk Utility First Aid

Mac has a built-in disk repair software called Disk Utility First Aid, which you can employ to scan the corrupted flash drive and fix the damaged file system. Here is how to repair a corrupted USB on Mac:

  1. Click Launchpad > Other > Disk Utility.
  2. Select the corrupted drive from the sidebar.
  3. Click First Aid at the top of the window, and then click Run.mac-first-aid-in-disk-utility
  4. Wait until the repair process finishes. If Disk Utility successfully repaired your USB flash drive, you can now open files on the drive.

Recover Data Using Bitwar Data Recovery Software

If unfortunately, you come across data loss during the above methods, we recommend you immediately use a professional data recovery tool to recover your lost data like Bitwar Data Recovery Software. This software is the best USB data recovery software that supports recovering lost files from unreadable USB flash drives from Samsung, SanDisk, Toshiba, Lexar, PNY, etc.

The following are the steps to recover lost data from the USB flash drive using Bitwar Data Recovery Software on Mac:

  1. Download and install the software from Bitwar Official Website.
  2. Launch Bitwar Data Recovery Software, then select the USB flash drive and tap on Next.bitwar data recovery software Mac Select-Partition
  3. Choose the desired Scan Mode and continue with the Next button. bitwar data recovery software Mac scan mode
  4. Choose the File Types of the deleted files and followed by clicking Next.bitwar data recovery software Mac file types
  5. Filter and Preview the scan result from the software. Then click the Recover button to start the recovery.
NOTE: Save all the files to a new safe file location instead of the original file location to prevent data overwritten!


This article introduces you to four methods to fix a USB flash drive unreadable on Mac. Besides, when you encounter data loss, Bitwar Data Recovery Software will help you recover lost data from the USB flash drive.

How useful was this post?

Click on a star to rate it!

Average rating 5 / 5. Vote count: 1

No votes so far! Be the first to rate this post.

We are sorry that this post was not useful for you!

Let us improve this post!

Tell us how we can improve this post?

Related articles



Please enter your comment!
Please enter your name here

Share article

Latest articles

Popular articles