• Stellar Drive Defrag

Stellar Drive Defrag

Proficiently seeks out scattered data fragments on Mac volumes (including Boot volume) and organizes them at contiguous memory locations


Mac Disk Drive Defrag software improves data access speed and Mac’s performance by defragging files on hard drive including the Startup Disk.

  • Logically groups scattered pieces of related data to improve data access speed
  • Supports defragmentation of Encrypted hard drives and Mac volumes
  • Defrags metadata like catalogs, allocation files, extent overflows, and attribute files
  • Monitors temperature fluctuation of Mac hard drive during defragmentation
  • Provides an option to create a bootable DMG to defrag startup disk
  • Support macOS Sierra 10.12, 10.11, 10.10, 10.9, 10.8, 10.7, 10.6
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Key Features

Stellar Drive Defrag is powered by an impressive set of features that enables it to optimize system performance and improve system speed. The product allows users to optimize free spaces, apply color schema for similar data blocks, monitor drive temperature, etc. for free. Some of the salient features of the software are described below:

Defragments Mac Hard Drive icon

Defragments Mac Hard Drive

As data is written, modified and deleted on the Mac hard drive, contiguous blocks of storage soon become occupied. Soon, memory allocation reaches a stage where large data files can no longer be stored at a single physical location. So they are divided into fragments and scattered all over Mac’s storage. This causes a lag in the system while accessing information resulting in a significant performance degrade. Mac Defrag software uses efficient algorithms to collect logically related pieces of scattered data and allocates them to neighboring or nearby locations to reduce drive fragmentation, therefore, making data access easier and smoother.

Mac Disk Defrag Modes icon

Mac Disk Defrag Modes

This intuitive product allows you to defrag a Mac through more than one mode. You can select if you wish to perform a ‘Quick Defragmentation’ or ‘Full Defragmentation'. The Quick version allows you only to defrag the Mac volume that you have selected. This is a fast process. However, with Full defrag you can defragment Mac hard drive as a whole. This process takes a little more time but yields a much better system performance. The 4 defrag algorithms are - Quick, Full, Metadata and Optimize perfectly works to optimize an internal Mac hard drive and an external drive. The software doesn't support defragging a SSD.

Identify & Colorfully Arranges Everything icon

Identify & Colorfully Arranges Everything

The tool also defrags metadata and categorizes disk space into various attributes, such as Allocation, Overflow, Catalog, Attribute, Fragmented, Data, Unused Space, etc. Smart color schemes allow related memory blocks to be depicted through the same color. It even allows you to change the colors of memory blocks as per preference to help you plan Mac disk defrag better.

Graphically Monitors Drive Temperature icon

Graphically Monitors Drive Temperature

The Mac hard drive that is being defragmented can show temperature fluctuations during the process, typically, a steep rise in degrees. The software marks a maximum threshold level up to which temperature rise of the drive is acceptable. It depicts temperature fluctuations graphically on a scale to enable you to take action if it is nearing or about to cross the threshold level.

Free Space Optimization icon

Free Space Optimization

While performing Mac disk defrag, this tool scrutinizes portions of free drive space and arranges them together to create one large block of free space on the hard drive. This allows the Mac to allocate this space to one large file if needed and helps to further boost data access speed and overall Mac performance. In the absence of free space optimization, the OS X will save the large file(s) to non-contiguous hard drive's memory location causing performance degradation; which is why Stellar Drive Defrag << Free Space Optimization feature is required to fill this gap.

Defrags Encrypted Mac Volumes icon

Defrags Encrypted Mac Volumes

Mac Defrag software helps you to optimize encrypted and password-protected Mac hard drives. It prompts users to unlock the drive by entering the password, and once it has been unlocked, the software mounts the volume. Thereafter, users can select any of the four algorithms (Quick, Full, Metadata defrag, or Optimize) to improve their Mac’s internal or external encrypted hard disk drive performance.

View Location of File in a Block icon

View Location of File in a Block

When all data on the Mac has been categorized and arranged in different colored blocks, this product’s smart interface displays the full path of any file inside any block you place the mouse cursor on. Clicking on a particular block will display the file occupying that block as highlighted in the 'Files' view. This helps you quickly identify and trace all fragmented files on your hard drive.

Create Bootable USB icon

Create Bootable USB

In addition to Mac Defrag operation, the Stellar Drive Defrag tool facilitates bootable Mac USB creation. The tool provides an option to create DMG file, which can be used to create a bootable USB to boot Mac machine and also perform boot volume defragmentation. Note: Creation of a bootable USB is only required to defrag Mac startup drive and not non-startup volumes.

Send Email Notification icon

Send Email Notification

Once the defragmentation process is completed, the software allows you to send email notifications to an id that you specify. You can set the receiving email id through 'Preferences' on the 'Stellar Drive Defrag' menu.

Compatible with macOS Sierra icon

Compatible with macOS Sierra

OS: Sierra 10.12, 10.11, 10.10, 10.9, 10.8, 10.7, 10.6
Memory: 1 GB RAM
Hard Disk: 50 MB of Free Space




The process of optimization arranges the files together at one place. Defragmentation takes different parts of the files into a single chunk of contiguous memory.


Yes, with Stellar Drive Defrag application, you can defrag any file you want. If you click on the 'File' tab, the software shows the individual files in the selected volume. Select the file from the list and defrag.


No, there is no such constraint regarding the make/model/type of hard drive. The software can defrag any Mac volume based internal, external, USB drive irrespective of its size or any other limitation.


Stellar Drive Defrag supports the latest macOS Sierra 10.12. The software is also compatible with the earlier versions of OS X, including Mac OS X El Capitan 10.11, Yosemite 10.10, Mavericks 10.9, 10.8 'Mountain Lion', 10.7 'Lion' and 10.6 'Snow Leopard'.


Yes, the Mac drive defrag software can defrag and optimize the boot volume of your Mac system (i.e. startup disk Macintosh HD). However, for this, the software prompts to create a bootable USB first. You can boot the system from this bootable USB and defrag the boot volume. If you have ‘El Capitan’ installed on your computer, you need to download a bootable image ('.dmg' file) using the link provided by Stellar and then burn it to a DVD to defrag the boot volume of your system.


You can defrag a HFS or FAT formatted external hard drive using Stellar Drive Defrag utility. Learn more


Yes, the software can help you defrag the metadata files (catalog files, allocation files, attribute files, extent overflow etc.) of a system. You can use the 'Defrag Metadata' option to carry out this process.


No, Software does not support Power PC anymore.

Rating & Reviews


4.6 out of 5 stars


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User Comments



Your software fixed my ailing hard drive. Woot!!

Fawwaz Abdul


Defragging a Mac might sound absurd, but I had no choice but to eliminate the presence of fragments of 28 files. After getting it removed, I noticed positive change in the performance of Maps

Tyson Thurgood


Thank You So Much Stellar Drive Defrag. With your help, I managed to accelerate my Mac performance. Earlier, I had no clue why my MacBook Pro 2012 El Capitan 10.11.4 ran slow though having 4 GB RAM and enough free spaces on the hard drive. Defrag tool showed me the real cause which was disk fragmentation. After a successful defragmentation my MacBook Pro booted up quickly, and 3rd party apps performances have improved dramatically. Thank You Once again.



Before using this app, I had issues with my Mac OS hard drive due to slack space. But, once I used Stellar Drive Defrag app it removed all the slack space problem from my Mac and also proved helpful for improving my system performance significantly.



Optimised my 500 GB internal hard drive when no other apps could even come close to optimizing it.

Joseph Maultsby


My video library is huge and measures up to almost 450 GB of the hard drive storage. I work day around on video editors and my Mac runs on 16GB RAM and large 2 TB disk. Recently I began to notice sluggishness of my drive. My video editing became painfully slow and I realised that large files and bulky software are killing my Mac performance. I tuned up to this product which showed me the problem i.e. fragments. All of those files were badly fragmented and cannot be fixed without a defragger. This tool took great amount of time to fully defrag my HDD and removed all the fragments. With the restart I noticed the improvement of my Mac and with couple of more I witnessed a huge shift of performance hike.



Without a second thought I decided to optimize my iMac hard drive with Stellar Drive Defrag. OS X was lacking the responsiveness, goes into longer startup and gave me back spinning beach ball frequently. The demo version gave me an idea of the quantity of fragmented files occupying my iMac drive. Fragments were gigantic and could possible be removing only by formatting the disk. I tried Stellar Drive Defrag that gave me an option of creating bootable media through which I eradicated the fragments. As a result the boot time of the OS X improved, noticed better browsing and media players performance. The tool saved me from a hectic ordeal of backing up the Mac, formatting and reinstalling the OSX.



The best and fastest all around defragger and optimizer software for every Mac user.



I am a die hard fan of Stellar Drive Defrag utility since it boosted up my Mac disk running Mavericks 10.9.5. The UI is self explanatory and the software offerings to defrag Mac hard drive with four top algorithms is out of the box. I decided not to replace my hard drive after it was defragged and optimized by this amazing tool.

Elenora Mcnitt


Excellent tool to defrag encrypted file system. I revamped the performance of my 500GB external hard drive after enough of its sluggishness. No other defrag software offers this feature.



Had great success with Stellar Drive Defrag software after I booted up the Mac and kicked out those reddish blocks of fragments that were causing me a serious nightmare.



it takes hours of travelling from my house to the nearest Apple store. I needed to get my Mac back to work and your software just accomplished it for me. A big Thank You from Mexico.



I tried this piece of software on one my old iMac 2010 system that I was about to donate to my cousin. He wanted to start his learnings so I decided to optimize this iMac performance so that he is able to execute day to day tasks. To my surprise Stellar Drive Defrag improved it to a more than I expected and made this machine work better for a 5th grader.



This is one kick a** tool that surely outperform others and increasing your hard drive's performance.

Jeffrey Cook


I felt like throwing my Mac away after 4 years of its service since it begins to crawl almost everyday. Thanks to one of my friend who recommended me to optimize the Mac hard drive with Stellar Drive Defrag before deciding to let this Mac off. This software proved to be a savior and got back my Mac performance to an extent where I can use it for a year or more.


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