Best Free Disk De-fragmenter


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Fragmentation: why it happens

Suppose you are browsing the web, downloading your favorite songs and installing an application all at the same time, how does your system write all these files without any interruption to your activity? Well it's simple: it responds to all applications' write requests (I/O operations) by writing all files at a continuous location on your disk.

Representation of a disk track:

(Fig. 1)

Yellow: Temporary written internet files
Red: Installation (Game)
Blue: Song cache

The purpose of disk defragmenters is to reorganize such files which are supposed to be together. An ideal situation after defragmentation would look like this:

(Fig. 2)

But what happens when you uninstall, delete, or simply clean your temporary files? Imagine yourself uninstalling the application (game) you installed. The disk could look like this:

(Fig. 3)

The white zone is empty space without fragmentation. A disk looking like this will have just a little or even imperceptible impact on performance. In this case defragmentation is needed but not critical.

The last thing you want to see is a hybrid combination. Files very fragmented fig 1 and empty disk space fig3 but instead of contiguous clean sectors you'll find what we call fragmented empty space. And this is what it looks like:

(Fig. 4)

This is the worst case scenario. Overall system performance will be compromised and fragmentation is critical. You should defragment (defrag) or let your defragmenter schedule and execute the defrag process for you.

Standard mechanical HDDs (hard disk drives) will benefit from defragmentation and continuous disk use, because when spinning it keeps remagnetizing the HDD plates. But if you own an SSD (solid state drive) you SHOULD NOT defrag or install any defragmenter application because it will shorten the life of the drive.

So when testing defragmenter software we are going to evaluate it with some parameters:

  • Speed of analysis on fragmented files: Isn't it speed we want from our computer?
  • Speed of defrag
  • Some extras: such as scheduled defrag, shutdown PC when done, etc.
  • Defrag capabilities: why is this placed in last position? Because almost all of today’s defragmenters can perform this task with very similar results.

Well, it's time for action now and let me introduce you to the de-fragmenters.


UltraDefragUltraDefrag is simple yet has a lot of customizable options through text files and scripts via two mouse-clicks. Not only is the defragmentation super fast, but also you are not going to notice it's working! You can keep doing your things while UltraDefrag does what was born to do… defrag. It performs so well you are going to want to carry it in your wallet. A lot of varied boot defrag commands. If your goal is to optimize your system startup at maximum, this is what you need.


MyDefragMyDefrag, JK defrag with a GUI (Graphical User Interface). Bad? No, just awesome!

Unbelievable power user options for everyone without having to configure any script. Just select the option that best suits your needs and it's done. MyDefrag employs an algorithm that places the most used files at the beginning of the disk. This decreases access times because the actuator arm of the hard drive has no need to move to the end of a disk to search a file.

If you don't know what a HDD looks like, please see below:

The trick revealed and a little science.

When you turn off your computer (or Windows shut downs your HDD), the actuator arm has a designated "landing zone" (a specific sector at the beginning of the disk) that remains stationary until the next startup. This is to avoid disk scratch and therefore, data loss (data is read via magnetism, touching surfaces is not required). When turned back on, the closest sector to the actuator arm is already near the "landing zone" (beginning of the disk) so it's faster to read files on that sector than others in outer zones of the disk.

Also, the surface distance travelled is considerably less in the inner sectors of the disk. So, placing files at the beginning of the disk is the best idea.

MyDefrag is not the only defragmenter capable of doing this, as many others include an option. However, MyDefrag achieves this in a much simpler way. This is combined with a good “fast defrag”; the choice of specific options, many others by scripting, and excellent defragmentation methods and simple scheduler options.


This little boy, DiskTune, is not exactly a kid. Despite the use of Windows API to do defragmentation jobs, it's incredibly fast, simple and lightweight. Many useful options just a couple pixels of distance. Direct access to usual options such as Analyze, Defrag (quick), Optimize (rearrange) and Compact (defrag free space). The best thing about DiskTune? The ability to create a shortcut to your desktop and then double-clicking it to run a fully customized defrag. Four words—“one size fits all”.


Defraggler thumbnailPiriform's Defraggler—The first thing that caught my attention when first opening Defraggler was a green word, GOOD. I quickly realized it was telling me about S.M.A.R.T. Status (information provided by the disk itself, reporting temperature etc). This is a great feature and has its own tab on the program for detailed view.

In terms of defragmentation ability, Defraggler is one of the best choices you could make. It performs a very fast “quick defragmentation” with decent file reorganization but if you perform a complete defrag process, which takes longer, you obtain results that are worthwhile. Your files will be together as they should be as solid as a concrete wall. Defraggler also supports scheduling, low priority and boot defrag. Highly recommended.


MyDefragmenterMyDefragmenter, Ultradefrag with a very simple, intuitive GUI plus a full scheduler which has the ability to program defrag while shutting down or starting up computer. Includes a 24/7 support by phone call and online help.


Auslogics Disk Defrag thumbnailAuslogics Disk Defrag is another quality disk defragmentation program. During a fresh installation the installer asked if I wanted to install a Tool Bar and/or change my home page. These were easily de-selected before the installation process began. Auslogics Disk Defrag can be ran from a easy to understand GUI (Graphical User Interface) or you can use the command line tool for more advanced users. Auslogics also optimizes defragmented files and space by defragmenting free space and moving system files to the fastest part of the disk. The software is designed to defrag multi-terabyte volumes. If you choose you can defragment a particular folder or a single file by selecting the file out of a list of fragmented files. The program is set-up for automated defragmentation and will allow you to analyze your disks before you defragment. Auslogics also has a portable version available which can be run directly from your USB drive. Both versions are free and are allow for home or commercial use. The developers also have several articles regarding defragmenting your hard drive including How to defrag your drives the right way: 7 defrag tricks to learn today". This article includes topics such as temporary files and how to prevent the loss of your system restore points. The software only supports 64 bit on Windows 7/8 operating systems. The developers have updated this software twenty-four times in the last thirty four months, eleven of those were in 2012. Needless to say continued development of the product remains strong.  I have used this program on all of my computers for the last couple of years without any issues. Operating systems I have successfully operated on include XP 32bit; Windows 7 32 & 64bit.


Also reviewed but not included:

-Puran Defragmenter

-O&O defrag free edition



Feel free to suggest any software not already mentioned for review.

Quick Selection Guide


Gizmo's Freeware award as the best product in its class!

Runs as a stand-alone program on a user's computer
System files defragmentation. Incredibly fast in all tasks. Power (scripting) features.
Some settings only accessible by configuration file (txt).
681.6 KB
32 and 64 bit versions available
Open source freeware
A portable version of this product is available from the developer.


Runs as a stand-alone program on a user's computer
For average and power users
Not regularly updated
2.035 MB
32 and 64 bit versions available
Unrestricted freeware
There is no portable version of this product available.


Runs as a stand-alone program on a user's computer
Very Fast. Can create shortcut to double click customized defrag.
Windows API. Needs to improve system resources usage
1.06 MB
32 and 64 bit versions available
Unrestricted freeware
There is no portable version of this product available.


Runs as a stand-alone program on a user's computer
Very solid piece of software. Updated regularly. Now with S.M.A.R.T. monitoring.
No optimization feature yet.
3.6 MB
32 and 64 bit versions available
Free for private use only
A portable version of this product is available from the developer.

Auslogics Disk Defrag

Runs as a stand-alone program on a user's computer
Very fast at analyzing and performing a quick defragmentation.
Optimize function could be faster.
5 MB
32 bit but 64 bit compatible
Unrestricted freeware
A portable version of this product is available from the developer.


Runs as a stand-alone program on a user's computer
Well recognized Ultradefrag engine. Excellent scheduler.
Not regularly updated.
1.8 MB
32 bit but 64 bit compatible
Feature limited freeware
There is no portable version of this product available.
Running on x64 computer requires download and replace DLLs available at Mydefragmenter website

This software review is copy-edited by Ian Richards. Please help edit and improve this article by clicking here.

defrag disk, defragment hard disk, disk defragmenter, free disk defrag software.

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OK - will let you know what I find.


"my defrag" totally screwed up my hard drive. I dl'd it and ran it one time. It made ALL my movies unusable, and to make matters worse I went from 8% fragmentation to 32% at completion! It took days to straighten out, and if I wanted to fragment my sys I couldn't of done a better job of screwing it up than this one did!

I used it prior to switching to UltraDefrag. I never had an issue like that, but I have read a few horror stories with different defragmentation tools. I've even read about a couple from the built-in Microsoft Defragmentation tools. Hindsight is 20/20, but the best thing to do is backup all of your important files. For me, that includes Music and my movie collection. Like a true geek, I love movies and have a re-purposed Desktop running XBMC, a NAS, and I stream my music and movies. Creating an image or "clone" of your hard drive is another backup method that allows the drive to be restored as it was at the time of the imaging process. Gizmo's has a page for this type of software: Anyone wanting some extra protection should definitely check this page out. I am a LAN manager by day, and I have a LUN (drive space) set aside for my desktop techs to store images from different machines. I create images of my test server before applying hot-fixes or patches for testing. It is a common practice for home users and professionals. Again, I am sorry to hear what happened to your hard drive, but until the size increases and the price decreases, solid state drives will not be a viable substitute for defragmentation. To maintain efficiency on traditional drives, de-fragmenting the drive is the best practice for reversing the chronic degradation of drive performance. For the state agency I work for, I am required to "defrag" my drives quarterly. Within the agency, 2 of the tools listed on this page are widely used: Defraggler and UltraDefrag. Thanks for sharing your stories, leaving comments, and reading mine! Take care! -rmitch45 a.k.a. Robert
I have a comment I want to add to the repeat "seminar writer", to borrow a phrase used in talk radio. This means that I repeatedly receive a very similar post, under the guise of a normal reader who wants to share, but the post comes from someone from a particular company trying to advertise a specific software. The posts always involve O & O, and how wonderful it is. I have tried O&O, it works, but if it were one of my favorites, it would be in the top 5. I hope that ends the repeat messages. Thanks everyone! -rmitch45 (Robert)

I'm sorry but Disktune will no longer be available. A second release was planned but Joep (the man behind Disktune) in that time told me "So, yes, I do have plans for the tool, just need to find the time" but that was in October 2012. It's sads news for everyone. Anyway, thanks Joep end thanks Disktune for such great piece of software.

Thanks for the update. I will keep my fingers crossed that he finds the time to create a newer version. It has been a long lived, solid, and effective tool.
I appreciate the extra information and an independent verification of what I read. Perhaps down the road, we will see a new release. DiskTune was heavily downloaded and used by many people around the world. Independent testing and use verified that DiskTune is one of the best de-fragmentation tools out there. It was in the top 5 when I was offered the opportunity to serve as the editor for this page. My testing and use of the product convinced me to leave it right it was. I still have it running on several family members computers. It is sad, and I don't really know if there is another product out there worthy of moving into the list. I will look around and test some more to see. Thanks to all of you for sharing information, confirming information, and using the products we feature here! Take care and have a great weekend. Most Sincerely, Your De-Fragmentation Editor rmitch45 (Robert)

I think DiskTune may now be discontinued. It doesn't seem to be listed on their site and the link to it above doesn't work btw.

There are going to be many sad users of DiskTune. In a reply to a consumer on June 3rd, 2013, one of the company's developers verified that DiskTune is "discontinued for the time being". I have not been able to find any details on why the product is no longer available. If anyone happens upon an explanation, please share it with me. I am extremely curious why such a popular product has been abruptly discontinued. Thank you again mrfingerz. I have confirmed your assumption and will submit a site change to my peers without DiskTune included. Take care, Robert (rmitch45)
I thank you again. The creators of the product are still and around. New hard disk software is available, but the focus is hard disk repair for file recovery and forensics. As I stated earlier, the Softpedia link is still good. It looks like support and quite possibly development of DIY Data Recovery is being discontinued. I would advise all readers to use one of the other products until I can identify the best replacement for the product. I will do some more research on the possibility of a future release, but I expect after I can confirm the de-fragmentation tool will no longer be supported, I will remove it from the top five. I will look at my test data and do additional testing to see if another product is solid enough for the list. My favorite, UltraDefrag, is still available, supported, and updated regularly. Sincerely, Robert (rmitch45)
Thank you very much. I will check to see if the website is temporarily down or possibly migrated or abandoned. If you want to give it a try, the Softpedia link still offers you access to download the latest version. I have spent a lot of time the last couple of weeks installing an Intrusion Detection/Protection System at work. It has made me think about what most malicious hackers are after, information. In particular, the crooks are looking for PII (personally identifiable information). With Smart Phones, tablets, pads, laptops, and Ultra Books saturating the market, security is not just a business concern anymore. It should be a personal concern. This wonderful site is a large library of articles and products you can use to protect your personal information. I first learned the word "Hardening" in a Comp-TIA Security + class. It is simply the act of taking actions to correct security vulnerabilities and minimizing the possibility of a breach. All Web Browsers have vulnerabilities. Start your personal security training by reading Chiron's article How to Harden Your Browser Against Malware and Privacy Concerns. This is only one of many great security resources available on this site. Here is URL for your convenience: This is a sound start to protecting yourself. Please check out the free VPN services on this site as well. In any public location, browsing the web is a lot safer when your information is encrypted and bounced around through Servers all over the world. Everyone take care and have a safe, enjoyable weekend! Sincerely, Robert (rmitch45)
Although UltraDefrag is a great product, what I don't like about it is that, it leaves a file behind on every drive that's been scanned. Although on this page it says that if reporting is disabled, then no files would be left behind.
I have verified your last comment that if reporting is disabled, the file is not left behind. I appreciate the information. Even as much as I have used the product, I did not think about the log file or that it can be disabled.
This is not a reply to my previous comment, but rather an unofficial commentary for those of you who prefer Microsoft's built-in De-Fragmentation utility. I hope you enjoy the commentary and respond with your own experiences. The pseudo-article is double spaced to make it easier to read. All of the writing is my own original work except for the cited quote from TechNet. June 20th,2013 rmitch45 a.k.a. Robert Windows 7 and Windows 8 native De-fragmentation As I have written before, the built-in de-fragmentation software for Windows is much improved. I happen to believe this is at least partially the result of so many free and commercial software offerings that provided features and functions that were missing in the Windows De-fragmentation tools. Alone, the native Operating System De-fragmentation tool from Microsoft still lack some good features and functions. Sysinternals started off developing software that added many of most popular commands and tools found in UNIX and Linux Operating Systems. Most IT technicians are at least familiar with the Sysinternals “PS Tools”. Microsoft embraced the efforts of Sysinternals and purchased the company and the suites of specialized tools. Page Defrag is one of those tools that were developed by Sysinternals during the early 2000’s. According to TechNet; “PageDefrag uses advanced techniques to provide you what commercial defragmenters cannot: the ability for you to see how fragmented your paging files and Registry hives are, and to defragment them” (Russinovich, 2006, To correct the older TechNet description , there are other free De-Fragmentation software packages that have the capability de-fragment your paging file and registry hives, but PageDefrag adds this capacity to Microsoft’s built-in tool. I have use PageDefrag before, and the tool does what it is intended to in a pretty easy and intuitive way. The Microsoft Operating Systems’ built-in de-fragmentation tools are still not in my top 5, but for many PC owners, it is their favorite and primary tool for Hard Disk maintenance. So; to those many devoted Microsoft users, this is a tool you may definitely want to give a try. The tool is available from Microsoft’s TechNet site, as well as many other locations. My personal favorite download site is Softpedia. This is not an official top 5, or a standalone website article. For those reasons, I will not include a link to the software. Instead, just open Google, Bing, Yahoo, or your favorite search site and type in “download Sysinternals PageDefrag”. At home I use UltraDefrag to perform de-fragmentation of the paging file. At work, most of the technicians use Defraggler, by Piriform, to handle the paging file. Both of these free de- fragmentation software tools are in the top 5 list at disk-de-fragmenter.htm one of the many Gizmo’s top free software categories. As always, thank you for your comments and support of both the de-fragmentation page and entire collection of awesome resources available at Please feel free to comment on your experiences with any of these free products or another free product in the same category. The website offers and focuses on free resources, so please refrain from commenting on “Commercially” licensed and purchased products. I hope you enjoyed the information. I look forward to hearing from others who may have used this Sysinternals supplement. Most Sincerely, Robert (rmitch45 current page editor)
I was attempting to respond to a predominantly negative post regarding open source and free software. Fortunately, one of the other editors or webmaster have removed the response. This does give me an opportunity to restate that I believe in and support the development and use of free software for a variety of reasons. Some, like the free de-fragmentation software, are developed to give computer users a better way, or more control, over maintenance tasks. In my opinion, Microsoft has improved its built-in defragmentation tool over the years because customers were seeking out and using alternatives that did a better job in less time. Both directly and indirectly, freeware advances the development of features, functionality, and competition in the digital marketplace. As always, thanks for visiting the site. Please check out some the other great categories and links. You might find just what you need.
To all, I have been testing quite a few de-fragmentation programs. When I finish, the list won't look much different than what is presently posted. Ultra-Defrag has continued to win out on speed, functionality, and ongoing coding to make the product better. Defraggler is still easy to use and well supported. DiskTune and MyDefragmenter still perform well. I have also used Auslogics and like the entire package of tools they offer, but I don't like the constant pop-ups and advertising to purchase the "paid" version. I am still looking at others with mixed results from very good to fair. I have also taken into consideration that the built-in Microsoft de-fragmentation tool has improved vastly. At some point, I will write about a couple of tools from SysInternals that add to the functionality of the built-in tool. Thanks for the comments and questions! Keep those coming. Also, Internet privacy is becoming a huge deal, so check out for VPN's and free VPN services. If you are constantly on the move, like me, you can check your bank account or place orders with an added layer of protection when you are on a shared or open wireless connection.

Sorry if repost.

My external hdd (seagate) has bad sectors. Do these defragmentation tools skip the bad sectors? Do they even detect them?

From what I read on the Windows De-fragmentation tool, since before XP, de-fragmentation can help prevent bad sectors, actively searches for bad sectors, and attempts to repair them. This exclude, of course, Solid State Hard Drives. I will still check further into my favorite, UltraDefrag, and see if there is any more information on the topic.
I've been at this a long time, but any IT Professional that tells you they know everything is probably suffering from narcissism. I believe that if the sectors are bad, the best de-fragmentation programs would skip over them. I will do a little research and post a question on the support forum for the number one program here, Ultra Defrag. The Open Source community is good at responding to queries and helping each other out. By the way, that is a great question. I appreciate it!
I will check the link again tomorrow and see if it is backup along with any other information that may be available. Thanks gentlemen!

About MyDefrag; Just a "heads up": appears to be down today. I don't know if that means it is dead or just offline but...

Definitely down as of now: Could just be server maintenance, or as you suggest something more severe. Time will tell. MC - Site Manager.

It came back on 10th April. Problem was with faulty dns-server, none could access the site although it was up and running.

Thank you! That means I don't have to hunt down another product with fewer features to fill a gap.
Thanks for the update. :) MC

Watch out. UltraDefrag just blew in the middle of an Optimization on one of my PCs running Win7. It's got plenty of power and space on the HD. My system is hosed for now.

Were you using a Beta version? Can you isolate the issue to a particular setting or specific action. I am only asking because the product has consistently been highly ranked, and after testing on my personal machines, the licensing permits use within government and business environments. I have substituted UltraDefrag on many Windows 7 machines within my workplace due to the faster defragmentation times as well as the optimmization. I have it on about 30 desktops now in place of Defraggler. It has been performing very well on the Dell Optiplex Systems I am using it on. Thanks for your feedback. A word of caution to all: The open source and free tools are offered as is. The Open Source products generally have an active group of followers that are ready, willing, and able to assist with any issues and bugs. In many cases, I find the forums for these products to have better support than paid software. You may want to pose your specific situation in a forum. SourceForge can probably link you to the community. Keep me posted.

Nope, I was using the newest stable version. I started the full slower optimization and left the house. Came back later to a shutdown PC. Started it up and got the message that Windows couldn't start. Two options... repair or start Windows normally. Starting Windows normally would just put me in the same spot. When I tried a repair, Windows gave me a message that it couldn't do it. Can't remember exactly what the message was. Luckily, I keep most of my stuff on an external drive! I would love to have been able to look at the events if Windows was able to log them. I still have the drive if you know where I could look for the events.

I also like the many options that this software gives you but I'm scared! Going back to Defraggler for now.

That is definitely unfortunate. The technician in me would love to look at the Event logs and the dump file. I am the editor of the defragmentation page on a voluntary basis as a way to contribute some of my experience and to answer questions related to this topic. Consequently, I have to be cautious about what I write and how I write it. I do not advocate that anyone opens or browses through Windows system files without the explicit warning that doing so can trash the Operating System. However, I can tell you that the log files are located within the Windows system files. More specifically, the .evt files are located within the %SystemRoot%\System32\Config folder. The files can be imported into a Comma Separated Values format (.csv)that is very similar to Excel. If you decide to have an IT Pro retrieve them for you, the answer to the crash will probably be in both the Application and System logs. As to Defraggler, it has always been stable, frequently updated, and on my personal top three list of de-fragmentation tools. I have installed Defraggler and it's sister program CCleaner on more machines than I can count. Defraggler will do a great job for you, is highly customizable, can be set to replace the Windows De-Fragmentation tool, and run automatically through a scheduled task. You can't go wrong with all of that. In my testing, if I find a negative impact on Windows from any of the products, I will certainly share that as part of creating an objective and unbiased list. Thanks again for sharing the information with me and the other readers!