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.
This version will install on PCs running: Windows XP / 2003 / Vista / Windows7 / XP64 / Vista64 / Windows7 64
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.
Windows 2000, 2003, XP, Vista, 2008, Win7, and for X64.
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.
This version will install on PCs running: Windows XP / 2003 / Vista / Windows7 / XP64 / Vista64 / Windows7 64
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
Unrestricted freeware
A portable version of this product is available from the developer.
This version will install on PCs running: Windows XP / 2003 / Vista / 7 / 8 /
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.
Windows 7, Vista, Windows XP

Running on x64 computer requires download and replace DLLs available at Mydefragmenter website

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.
Win 8 (32 or 64 bit), Win 7 (32 or 64 bit), Vista SP2 (32-bit only), XP SP3 (32-bit only)


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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Average: 4.1 (204 votes)
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by Anonymous on 10. June 2009 - 2:14  (23467)

I tried the Iobit SmartDefrag and it recommended a Fast Optimize. Yeah, right! Everything seemed to work fine until I rebooted. My boot time went from one minute to over four minutes. System Restore didn't help, so I did a complete reload. After several hours or updating, reinstalling, and restoring I am back to where I was, WITHOUT SmartDefrag. This is the second time this has happened (shame on me). There won't be a third. The first time was with JKDefrag. I'm not sure the optimize option is the right thing to do, so I'll stick with Auslogics Disk Defrag which an enhancement of the XP defrag but much faster and has never caused me a problem.

by Anonymous on 10. June 2009 - 16:07  (23512)

I have a problem with Smart Defrag too. I used it, started Deep Optimize and it started creating a lot more fragments! Now my drive went from a 10% fragmented to 90% fragmented! I'm serious! It finished, the report blank. I re-analysed, now it shows 1271 fragmented files and directories! You should have seen it creating loads more red blocks. Theres someting wrong with it!Smart Defrag has always being buggy and auto defrag never works and slows down the computer. I use Defraggler now, it does the job right, all software from Piriform just works. Just use all the software from Piriform, its all you need to maintain your computer.

by Anonymous on 10. June 2009 - 22:20  (23539)

OK. Time to move Auslogics Defrag to the head of the class. With v2.0, it now has options for Schedule, Exclusions, variable size Skip Large Fragments, Analyze only, Remove Temp Files Before Defrag, and Turn off computer after defrag. It will analyze and defrag selected disk(s). It also has increased speed and an overhauled interface. It still doesn't have an optimization option, but my negative experiences with that option would preclude my using it anyhow.
In my humble opinion, this is now the best of the lot.

by Anonymous on 11. June 2009 - 0:16  (23547)

I have to agree, although I think this was rather inevitable, Auslogics programs are in a different class to most.

by Anonymous on 13. June 2009 - 23:03  (23802)

The analyze function of Auslogics Defrag beta is dysfunctional. It shows a multitude of red clusters indicating fragmented files both before and AFTER defrag even though the count should be at or near zero after the defrag operation. It also doesn't include a report on which files are fragmented. Even the Windows defrag does that. This program seems to defrag the files ok, but the analysis before defrag seems to be window dressing with no real meaning. It is beta, so maybe improvements are on the way.

by Anonymous on 14. June 2009 - 2:56  (23823)

this is out dated

by Anonymous on 14. June 2009 - 20:42  (23881)

Better is to move JkDefrag to the head.

by Anonymous on 16. June 2009 - 13:33  (23985)

Diskeeper Lite v9 via Intel download quite good. Had been using v7 from MajorGeeks. Thanks.

by Anonymous on 16. June 2009 - 13:37  (23986)

you have to uninstall the v7 version first & then from the zip install v9 setup.

by Anonymous on 1. July 2009 - 16:07  (24547)

dont you dare get diydisktune...that $#!t crashed my vista and i had to factory image restore my computer. Ill hate DIY till the day i die.

by Anonymous on 2. July 2009 - 1:30  (24561)

I have been using Smart Defrag on Vista and to my surprise PCPitstop kept flaging 50% data defragmentation even though 0 files were fragmented. I had to run Vistas own Defragmentor to remedy the problem! I still run Smart Defrag but am wary of the fact that it may not defragment the data on the files it is reorganising.

by Anonymous on 3. July 2009 - 19:34  (24613)

Smart Defrag does the defragmenting part ie. put the fragments of files back together, but doesn't fully compact all the files to the beginning of the hard disk that removes all the gaps (consolidate), the built-in defragmenter in Vista does to more of an extent, so Vista's defragmenter was just compating the files to the front of the hard disk that Smart Defrag doesn't do, it's silly that Vista defragmenter does not show any details and a visual display of what it's doing, only an old progress bar that we see too much of in Windows.

I don't think Smart Defrag is good for that reason, seek times are reduced if the data is consolidated, data access is significantly faster at the beginning of the hard disk, also if the data is consolidated, it slows down the rate of re-fragmentation so consolidating is important. Hope I haven't confused you.

I think JkDefrag is the best, it's the only defragmenter that I actually notice a performance improvement after using. You can read more about it here-
If you want to give it a try, you can download the GUI here:
You don't need to download anything else, when you launch it, it will ask you to download everything that's needed and it will integrate it into the GUI program and its folder.

One thing I say to everyone, never pay for a defragmenter utility. There are free alternatives that do the job just fine such as JkDefrag.

by drewbee on 5. July 2009 - 19:32  (24672)

I am in the process of reviewing JkDefrag v3.36

So far I am really liking it. I am using it via liberkey. Which is an amazing freeware suite.


by Anonymous on 5. July 2009 - 21:01  (24675)

JkDefrag is the best. I'm liking it too! It does a thorough job of defragmention along with free space consolidation and then a fast optimization process. Popular blog "Insights and Rants" reports this program to produce the most performance benefit than most of the defragmentation programs out there right now.

by Anonymous on 5. July 2009 - 22:48  (24685)

I suppose every defragger has its strengths and weaknesses, there is no definite best free or commercial defragger. But you can keep up to date with the 2009 defrag shootout here:

by Anonymous on 6. July 2009 - 11:53  (24699)

The successor of JkDefrag, now called MyDefrag (still in beta), has a few improvments over JkDefrag, see here:

by drewbee on 7. July 2009 - 3:29  (24748)

Glad you like it! I will be updating soon :)

Please check back soon!

and also check out JKDefrag's sucessor MyDefrag

It's still in beta.

But I look forward to hearing what you think


by Anonymous on 8. July 2009 - 9:49  (24790)

It actually can run on Vista but it's not officially supported. In the JkDefrag GUI when you click to run PageDefrag it says that this version of PageDefrag will not run on this version of Windows, but I found a way that will make it work. In the JkDefrag GUI folder, click into the programs folder and click to pagedfrg.exe and select to defragment, no error pops up, and restart and it will run on Vista, it ran on my Windows 7 too without any error. It works!

by Anonymous on 17. July 2009 - 0:21  (25222)

MyDefrag have a version Final!Today!
Version 4.0 Final!Bravo!
Good Work

by drewbee on 17. July 2009 - 18:07  (25267)

Thanks! I've been waiting for it to get out of beta.

I will officially review this final version.

by Anonymous on 17. July 2009 - 18:52  (25268)

No problem

by Anonymous on 17. July 2009 - 23:10  (25277)

Yes testing Mydefrag 4.0 - looks good - gives a faster boot time compared to the others here - test for yourselves

by woodshed on 18. July 2009 - 11:25  (25302)

Just downloaded MyDefrag v4
Installed and running
Looks Good

by Anonymous on 18. July 2009 - 23:16  (25327)

Just one thik i don't like!...use much spu 60% when make defragmentation!

by Anonymous on 27. July 2009 - 9:28  (25824)

Never had any problems like that. Works like a charm.

by Anupam on 29. July 2009 - 8:03  (25917)

JK Defrag has turned into MyDefrag... so shouldn't JK Defrag be removed from the list? :D

Anupam Shriwatri

by Anonymous on 29. July 2009 - 8:54  (25922)

The link provided for Auslogics Disk Defrag homepage actually takes you to Auslogics Registry Defrag page!

by Anonymous on 29. July 2009 - 8:59  (25923)

I'm far from convinced about MyDefrag, I've found that it's Fast Optimize and Slow Optimize functions are actually significantly slower than the corresponding features in Smart Defrag on my Vista machine. It uses less resources sure, but that should only be an issue if you have struggling PC hardware IMHO.

by drewbee on 30. July 2009 - 21:39  (26039)

I believe Smart Defrag is a very good program Sir. As you can see from my review this product still received an 8 out of 10, a very good rating!

This being said, I still believe the experience of Mr. Kessels over at MyDefrag and JKDefrag are still superior to the Smart Defrag product.

I look forward to future Smart Defrag releases and I feel sure the program will improve.

Thank you very much for your input.

by drewbee on 30. July 2009 - 21:40  (26040)


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