JkDefrag Portable 3.36 Rev 2 (disk defragmentor) Released

John T. Haller's picture
Submitted by John T. Haller on May 29, 2012 - 12:49am

JkDefrag logoJkDefrag Portable 3.36 Rev 2 has been released. It's an easy to use disk defragmenter and optimizer packaged as a portable app so you can defragment and optimize your hard drives on the go. It includes a custom, easy-to-use interface to give you more control while still keeping everything simple. This release adds more-automated admin support and a greatly-improved launcher and installer. It's packaged in PortableApps.com Format so it can easily integrate with the PortableApps.com Platform. And it's open source and completely free.

Update automatically or install from the portable app store in the PortableApps.com Platform.


On-Screen Keyboard Portable ScreenshotJkDefrag Portable is an easy to use disk defragmenter and optimizer with lots of great features:

  • Fast operation
  • Lightweight
  • 64-bit support
  • Can defragment very full harddisks
  • Can defragment very large files
  • Custom made GUI for ease of use
  • Allows the selection of any combination of drives
  • Displays fragmentation percentage after analyzing
  • Disabled flash media by default to discourage users
  • Ability to run from a user account by prompting for an admin username and password

Learn more about JkDefrag...

JkDefrag's successor, MyDefrag, is closed source; so is not a direct successor in many respects. We will have it available in portable form shortly but will continue to make the open source JkDefrag available as well.

PortableApps.com Installer / PortableApps.com Format

JkDefrag Portable is packaged in a PortableApps.com Installer so it will automatically detect an existing PortableApps.com installation when your drive is plugged in. It supports upgrades by installing right over an existing copy, preserving all settings. And it's in PortableApps.com Format, so it automatically works with the PortableApps.com Platform including the Menu and Backup Utility.


JkDefrag Portable is available for immediate download from the JkDefrag Portable homepage. Get it today!

Story Topic:


The download link is broken. You can easily find the correct link in this case because the JKDefrag folder is the second folder in the top of the list of downloads that you are presented with when you click the current link.

I used to have a sig...until one of the mods ate it

John T. Haller's picture

There was a typo in the link. Sorry about that.

Sometimes, the impossible can become possible, if you're awesome!

Update attempts this morning yield a pop up that says

"The downloaded copy of JKDefrag Portable is not valid and cannot be installed".

Seems like something still needs a tweak or two.

John T. Haller's picture

It was still using the old MD5 sum in the updater database.

Sometimes, the impossible can become possible, if you're awesome!

Hi John,

Hope this comment finds you well.

In relation to packaging MyDefrag 4.3.1 as a portable app, you may find the following in-depth defragmentation analysis interesting.

Having no affiliation with site or author, I remain completely impartial and decided to perform my own simplified tests in a VMware virtual Windows 7 machine (host partition was newly formatted to reduce external influences, vmdk guest partition was replaced each time with original fragmented version).

Inside virtual PC,

Built-in Windows 7 defrag:
Once desktop finished loading, launching Blender takes around 31 seconds

Smart Defrag Portable:
Once desktop finished loading, launching Blender takes around 29 (sometimes 33) seconds

MyDefrag 4.3.1 ('System Disk Monthly' script)
Once desktop finished loading, launching Blender takes around 7 seconds

In closing, is it possible to replace my account name with my real name, will add signature saying "Formally known as db4tech), it would be a shame to lose nearly 5 years account time.

Hi John, further to my previous comment.

After being so impressed with MyDefrag, I have created (my very first portable app) a development test version of MyDefrag 4.3.1, everything seems to be working but have a few small questions.

For first time developers, where is the best place to share the file with you for testing / comments, development section of the forum?

Thank you kindly for your time,


John T. Haller's picture

Those stats are, honestly, a bit hard to believe. I attempted to replicate, but Blender in my Windows 7 x64 virtual machine within VirtualBox launches in about 3-4 seconds on my new i7 workhorse with the virtual disk running from a 2TB SSHD. It does that on a base install, with Windows defrag and with MyDefrag's Systen Disk Monthly (which takes quite a bit longer to run).

Sometimes, the impossible can become possible, if you're awesome!

Thanks for your reply and tests.

Since still have a copy of the original fragmented Windows 7 x64 virtual machine, can try recording some small videos if helpful?

My VMware virtual machine is located on the last partition (I know, not optimal location Smile ) of an 3TB HDD.
The PC technician side of me would recommend, if possible, even though modern SSD's are very robust, it's best not to test defragmentation software on an SSD due to unnecessary writes. Do you have a spare HDD?

Speaking of which, sounds like Christmas has come early for you, having a 2TB SSD, very nice! Smile

Agree, MyDefrag 'System Disk Monthly' can be quite slow compared to Windows defrag, but seems worth the wait based on thorough data structure optimization.

Edit: Oops! Just realised, you have a Hybrid drive, not 2TB SSD.

John T. Haller's picture

It's a 2TB SSHD aka HDD+SSD aka a hybrid drive. Specifically, it's a Seagate 2TB HDD with an 8GB MLC SSD within it as well as a 64MB cache. I have a 256GB SSD as my main, though. My primary dev box died, so I took out a line of credit to buy a new PC on Dell since I couldn't afford a new box. Otherwise I wouldn't be able to keep developing PortableApps.com. I have a spare HDD in the PC that's not hooked up, but probably won't as it would require a bit of time to reconfigure. I don't think I have a spare SATA cable, anyway.

I got permission from the MyDefrag developer a while back to make a packaged version but never saw the need since JkDefrag worked fine and modern Windows has automatic defrag anyway. You're free to package and post it and we can push it out later. It's a dead app for about 4 years now, of course, so I don't know how much interest there will be in it. But I'll push it out if folks are interested.

Sometimes, the impossible can become possible, if you're awesome!

I also have a 256GB SSD as my main. If helpful and you can afford the space, leave 40GB un-partitioned at the end and it should automatically be added to the drives over provisioning, your drives performance will be maintained and can even gain a slight boost as data re-allocation is helped.

As an aside, its almost painful to go back to having a system disk (virtual) on HHD but okay for experimenting and testing.

Great. There may still be future MyDefrag development. Found a link from a few months ago, developer mentions MyDefrag is just frozen for now.

Using your helpful tools and information, I have already packaged MyDefrag but few hours ago may have found an issue, scripts are working but (on a Windows 8 virtual machine) did not provide the normal detailed information. Being my fist attempt, I still have lots to learn.

Do you have a private upload area, thought best restrict universal access until you give the go-ahead or can email since its tiny, 850KB?

Maybe the in-depth defrag analysis on the site previously linked will pique a fresh interest in MyDefrag and a portable version, especially so if developer mentions it on his site?

John T. Haller's picture

It's a Samsung 840 Pro drive, so kept with the Samsung Magician recommendation of setting aside 10%. I also enabled the 1GB RAM cache for the drive. Put together, they make the system fly.

As for MyDefrag, it's been frozen for 4 years now. The developer said he might continue development at some point back in March and again a few weeks ago. That's not exactly looking rosy. As for the JkDefrag sources, they were open, so we built a (similarly) open source front-end for it to make it a lot easier to use... the same type of UI that freeware and paid defrag utilities use. I never did it for MyDefrag because, as freeware, it can be discontinued at any time or the publisher could change his mind for our permission and all our work would be a waste. That's why I wouldn't be interested in updating our UI for MyDefrag. Someone else could, of course.

Since you're just portablizing the basic UI included, it shouldn't be too much work to get up and running. You can post a public Dev Test of it with a live download to include MyDefrag. Our final version will bundle it, but I need to check if the publisher had asked for a review version before we released or not.

Please contain future discussion in a new topic in the forums as it's not related to this news story of a JkDefrag release.

Sometimes, the impossible can become possible, if you're awesome!