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Disk defragmentation and optimization tool.

3.8
Based on 123 user ratesRead reviews & comments
Free
Absolutely Free

iDefrag overview

iDefrag helps defragment and optimize your disk for improved performance.

iDefrag Features
  • Supports HFS and HFS+ (Mac OS Extended).
  • Supports case sensitive and journaled filesystems.
  • Supports adaptive hot file clustering ("Hot Zone").
  • Four powerful defragmentation algorithms:
    • Compact data, moving all free space to one place.
    • Optimize filesystem metadata.
    • On-line defragmentation.
    • Defragment whilst your disk is mounted.
    • Advanced programmable optimization.
    • Rearrange your disk the way you want.
  • B-Tree metadata file compaction/optimization support.
  • High-performance user-defined file classification engine.
  • Per-block and accurate whole disk display.
  • Detailed statistics so you know whether you need to optimize.
  • Inspector allows you to view details of individual extents/files.
  • Quickly jump to specific files to examine them in more detail.
  • Altivec accelerated display for improved performance.
  • Auto-update feature ensures you always have the latest version.
  • Fine-grained security, just like iPartition.
  • AppleScript support.

Note: Coriolis Systems Limited is shut down and does not provide any support for its products. The license information can be obtained from the Coriolis Systems' website

What’s new in version 5.3.1

Updated on Jul 10 2019

Version 5.3.1:

Note: This product is not compatible with macOS Mojave and later.

A free license from the developer is available here

iDefrag for macOS 10.10-10.11
iDefrag for OS X 10.6-10.9
iDefrag for OS X 10.4-10.5
iDefrag for OS X 10.3

View older iDefrag updates

Information

License

Free

Size

14.2 MB

Developer’s website

https://coriolis-systems.com/

Downloads

302055

App requirements

  • Intel 64
  • OS X 10.12 or later
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  • Comments

  • User Ratings

deanolatte
deanolatte
Feb 13 2023
5.3.1
0.0
Feb 13 2023
0.0
Version: 5.3.1
I used this to defrag ever since it came out. However, I stopped using it since os x Lion. I now find I need it, so, I downloaded it with the license key yesterday. However, the company is off line and cannot confirm my purchase. I must have the original CD somewhere but I haven't used that in years. Is there a way to get through the problem to get it working again?
Aargl
Aargl
Jan 2 2022
5.3.1
0.0
Jan 2 2022
0.0
Version: 5.3.1
You can read nearly everywhere that defragmenting is now useless and probably was never neededin MacOS: well, there's at least a few areas where it's really helpful, such as sparsebundles, if you use them. Not only it allows you to reclaim free unused space (and sometimes a lot!) but the disk is mounting faster and all operations that use it benefit from defragmentation. I've got mail archives from 20 years of Microsoft Outlook identities stored that way and the difference was plain to see! Thanks a lot Coriolis.
philstar22
philstar22
Jan 21 2021
5.3.1
0.0
Jan 21 2021
0.0
Version: 5.3.1
Well, neither my main hard drive, no the external hard drive I actually downloaded iDefrag to defrag actually showed up in the program, so it was completely useless to me. The only thing that showed up, in fact, was the disk image installation thing of idefrag. Strange.
dominym363
dominym363
Oct 28 2020
5.3.1
0.0
Oct 28 2020
0.0
Version: 5.3.1
Can someone explain what the license to use this program is. What is a license file?
lgm1146
lgm1146
Jul 7 2020
5.3.1
3.0
Jul 7 2020
3.0
Version: 5.3.1
iDefrag required to restart my mac to be able to work with the hdd (which is only one in my mac, where is also OS installed) and now it got stuck for more than 10+ hours in the loading screen (apple logo - at startup)... should I abort it by turning off the mac? Anyone knows it's frozen or what should i do? Thanks a lot guys
muffinstructer
muffinstructer
Jan 3 2020
5.3.1
0.0
Jan 3 2020
0.0
Version: 5.3.1
so i would rate your app cause i am a beta tester ,but the problem is i never got to try it it downloaded fine but when it was opened i recived a msg that it was damaged and to toss it out so thats what i did .something you should look into .let me know when you have fixedit and i will give it another shot
neartheredrocks
neartheredrocks
Jul 9 2019
5.3.1
5.0
Jul 9 2019
5.0
Version: 5.3.1
A huge "Thank You" to the developer! I wish you all the best for the future. Both applications, iDefrag and iPartition, are outstanding.
Fariborz
Fariborz
Jul 9 2019
5.3.1
5.0
Jul 9 2019
5.0
Version: 5.3.1
I did benefit from this nifty utility for many years and now it’s gone for good. At least the developer has been generous enough to offer it for free to those who still use the older Systems. Just go to their site to pick up your free license. Fariborz AMIRSHAHI - Verona (Italy)
djrobmoore
djrobmoore
May 11 2019
5.3.0
0.5
May 11 2019
0.5
Version: 5.3.0
Free?? Why is it asking me do drop my license when I try to install it?
pa-geographer
pa-geographer
Apr 22 2018
5.3.0
0.0
Apr 22 2018
0.0
Version: 5.3.0
From the Coriolis website: "Support for this product has ended. iDefrag works fine on macOS 10.12 and earlier, but has some problems on macOS 10.13 (High Sierra). There will be no further updates or bug fixes; the product will remain available for download and purchase for the benefit of users running earlier versions of the macOS."
ted939
ted939
Jan 22 2018
5.3.0
0.0
Jan 22 2018
0.0
Version: 5.3.0
Hi MU community! I hope someone might be able to advise me here.

I recently upgraded my OS from 10.7 to 10.9.5, and I already had iDefrag 1.7.3 (229), which I'm using now.

As we speak, I'm about 14+ hours into a iDefrag Optimize on a 4TB external drive that only has 650GB used, and the Location Indicator is only about halfway through the populated area of the Whole Disk Display.
I'm wondering: Does this mean I have another 14+ hours left to wait for this, and if so, is this normal/OK for iDefrag to take some 14-28 hours to optimize 650GB on a 4TB drive?!

Here's my setup:

iDefrag
Version: 1.7.3 (229)
Algorithm: Optimize
Class Set: Default
Enable per-class sorting: SELECTED/CHECKED
Skip files that cannot be defragmented due to lack of free space: SELECTED/CHECKED

Computer
Model: Late-2011 MacBook Pro
Processor: 2.5GHz Intel Core i7
Memory: 8 GB 1333 MHz DDR3
OS: 10.9.5 (13F1911)
Startup Drive: 1.05 TB SSD SATA
Connection: MacBook Pro ThunderBolt 1 <--> Elgato ThunderBolt 2

External drive being defragged/optimized
Brand: Seagate
Model: Expansion Portable HDD (STEA4000400)
Size: 4TB
Connection: Seagate's USB 3 <--> Elgato USB 3

Dock/Hub
Brand: Elgato
Model: ThunderBolt 2 Dock

ALSO - Regarding upgrading from iDefrag 1.7.3 to 2.2.8 (per Corialis website suggestion for OS10.9.5):
a. What's the process?
b. What's the cost?
c. How would it benefit me (if at all)?

I look forward to some help, as my work is halted until I finish defragging some drives, and I'm wondering if I need to budget 28 hours of computer downtime per 650GB of hard drive defragging :-|

Thanks!
Frankeed
Frankeed
Dec 6 2017
5.3.0
0.0
Dec 6 2017
0.0
Version: 5.3.0
Anybody have any benchmarks that show an improvement in drive performance after defragging, as advertised?
Gazman
Gazman
Aug 11 2017
5.2.1
0.0
Aug 11 2017
0.0
Version: 5.2.1
I haven't tried the software but just wanted to point out that 'defragging' a modern SSD hard drive will have no benefits and will actually decrease the life of your SSD. See http://helpdeskgeek.com/featured-posts/should-you-defrag-an-ssd/ for more info.
Joseluismen
Joseluismen
May 13 2017
5.1.8
3.0
May 13 2017
3.0
Version: 5.1.8
While it is used the version recommended according to S.O works perfectly. If you install the 5.1.4 (or superior) in Yosemite or El Capitan, can damage the disc, so that there is to reformat and to reinstate everything.The system of updates of the program, must have had this in account.The last compatible version with Yosemite and Capitan is 5.1.3 and now it does not try to update to a later one, as it must be.It is a good program, and it helps enough to maintain discs in sequence. But from time to time, the updates are not without risk. Due to him, I have had problems several times, the last ones with the passage to Yosemite,and it makes a pair of months with these incorrect updates of iDefrag.In addition, it is possible that some problems that I did not know to identify also came to use one more an up-to-date version of the indicated thing.
JIMMY2006
JIMMY2006
Apr 25 2017
5.1.8
5.0
Apr 25 2017
5.0
Version: 5.1.8
It is very easy to use. Very useful to install it on old Mac hard drive and get more free disk space.
Eric•Woehler
Eric•Woehler
Apr 24 2017
5.1.8
4.5
Apr 24 2017
4.5
Version: 5.1.8
Long-time user (since version 1) - using it primarily for a series of external hard drives. I have 8 x 3TB drives for paired backups of my image collection. Lots of file transfers, editing, swapping etc. I use iDefrag to keep the drives in good working order. Every 2 months or so, full defrag helps to maintain drives and all my precious backups in good working order. I was caught up in the registration snafu but all of my experiences with dev over the years has been v positive - I am in Australia and I get a response the same day or within 24h. Recommended software and supoortive dev - worth looking at iDefrag for protecting your drives.
Rjmorita
Rjmorita
Jan 16 2017
5.1.7
0.0
Jan 16 2017
0.0
Version: 5.1.7
Is it still necessary to defragment a drive any more? I've been told that it is not needed if you're running the newer OS such as Sierra. And of course, you cannot (or should not) defragment a SSD.
Mikebenda
Mikebenda
Jan 16 2017
5.1.7
3.0
Jan 16 2017
3.0
Version: 5.1.7
Every. Single. Time. I launch this app I am required to find and drag my license key file into the verification window. Every. Single. Time.
henri-spagnolo
henri-spagnolo
Dec 15 2016
5.1.3
0.0
Dec 15 2016
0.0
Version: 5.1.3
Warning with version 5.1.5. I use an iMac with Sierra 10.12.2. After having updated iDefrag to 5.1.5, the Mac was very slow at startup and also impossible to shutdown. Impossible to run a Disk Utility or OnyX or Time Machine. I have contacted the developer but no news for now.
Levelbest
Levelbest
Jul 14 2016
5.1.2
0.0
Jul 14 2016
0.0
Version: 5.1.2
I am not pleased with this developers idea of customer loyalty. I have used iDefrag for many years and in truth I find no fault in the way it performs - mostly. I stopped using iDefrag about 5 years ago. I was having a good deal of trouble with it’s licensing and DRM set up. I was using a hackintosh setup and while their DRM was part of the problem, my set up could have contributed to it as well. I finally gave up. I now use an iMac and have returned to the mainstream Mac fold. I am ready to revisit iDefrag as they have continued to improve their software and a few versions have gone by since I was a customer. I am willing to try again if they would offer an upgrade to a former user (and fan). Sadly, they do not. A line was drawn in the sand and some users were left on the other side of the line. Version 1 users must repurchase a license as new. All other versions will qualify for an upgrade price. I wrote the developer and asked to renew, but I was flatly refused. I appreciate that a developer has to earn a living but I also appreciate good customer service. A returning customer after 5 years who left at least in part due to the software having technical difficulties should, in my opinion not have to start over and repurchase a license when upgrade pricing is available. Isn't that at least a part of what upgrades are for, to reward loyalty? Sadly this is not the case with this developer. Your mileage may vary.
lgm1146
lgm1146
Jul 7 2020
3.0
Jul 7 2020
3.0
Version: null
apk412
apk412
Jul 11 2019
3.0
Jul 11 2019
3.0
Version: null
neartheredrocks
neartheredrocks
Jul 9 2019
5.0
Jul 9 2019
5.0
Version: null
Fariborz
Fariborz
Jul 9 2019
5.0
Jul 9 2019
5.0
Version: null
djrobmoore
djrobmoore
May 11 2019
0.5
May 11 2019
0.5
Version: null
Jim-Guy
Jim-Guy
Apr 29 2018
4.5
Apr 29 2018
4.5
Version: null
lithenirish
lithenirish
Sep 21 2017
3.5
Sep 21 2017
3.5
Version: null
Miguel-Cunha
Miguel-Cunha
Aug 13 2017
5.0
Aug 13 2017
5.0
Version: null
Joseluismen
Joseluismen
May 13 2017
3.0
May 13 2017
3.0
Version: null
JIMMY2006
JIMMY2006
Apr 25 2017
5.0
Apr 25 2017
5.0
Version: null
Eric•Woehler
Eric•Woehler
Apr 24 2017
4.5
Apr 24 2017
4.5
Version: null
Mikebenda
Mikebenda
Jan 16 2017
3.0
Jan 16 2017
3.0
Version: null
marcky
marcky
Jan 9 2017
2.5
Jan 9 2017
2.5
Version: null
F-John-Cianci
F-John-Cianci
Oct 16 2016
1.0
Oct 16 2016
1.0
Version: null
Markoh
Markoh
Jun 28 2016
0.5
Jun 28 2016
0.5
Version: null
Bggale
Bggale
May 1 2016
0.5
May 1 2016
0.5
Version: null
Pypo
Pypo
Mar 14 2016
0.5
Mar 14 2016
0.5
Version: null
weeste-1
weeste-1
Jul 25 2015
4.0
Jul 25 2015
4.0
Version: null
Hilbo60
Hilbo60
Mar 4 2015
4.5
Mar 4 2015
4.5
Version: null
WetNet
WetNet
Mar 4 2015
5.0
Mar 4 2015
5.0
Version: null
Moogan
Moogan
Mar 4 2015
5.0
Mar 4 2015
5.0
Version: null
StrictlyBagel
StrictlyBagel
Mar 3 2015
3.0
Mar 3 2015
3.0
Version: null
macbond
macbond
Mar 3 2015
5.0
Mar 3 2015
5.0
Version: null
Jcmyers87
Jcmyers87
Nov 19 2014
5.0
Nov 19 2014
5.0
Version: null
MOTOWNMAN
MOTOWNMAN
Sep 28 2014
5.0
Sep 28 2014
5.0
Version: null
P1H0
P1H0
Sep 15 2014
1.0
Sep 15 2014
1.0
Version: null
Jazzyguy
Jazzyguy
Sep 14 2014
5.0
Sep 14 2014
5.0
Version: null
Emile-b
Emile-b
Sep 13 2014
5.0
Sep 13 2014
5.0
Version: null
B-Jefferson-Le-Blanc
B-Jefferson-Le-Blanc
Sep 13 2014
5.0
Sep 13 2014
5.0
Version: null
bcasey
bcasey
Sep 13 2014
1.0
Sep 13 2014
1.0
Version: null
Eamonn-f7aaaaa5
Eamonn-f7aaaaa5
Mar 18 2014
2.5
Mar 18 2014
2.5
Version: null
Drxaz
Drxaz
Jan 23 2014
2.5
Jan 23 2014
2.5
Version: null
WalterT8575
WalterT8575
Dec 16 2013
5.0
Dec 16 2013
5.0
Version: null
Lightning
Lightning
Dec 10 2013
3.0
Dec 10 2013
3.0
Version: null
RavenNevermore
RavenNevermore
Dec 8 2013
5.0
Dec 8 2013
5.0
Version: null
Abramurkwian
Abramurkwian
Nov 16 2013
5.0
Nov 16 2013
5.0
Version: null
Purps
Purps
Nov 5 2013
0.5
Nov 5 2013
0.5
Version: null
Dejmac
Dejmac
Nov 3 2013
5.0
Nov 3 2013
5.0
Version: null
TAOGde
TAOGde
Nov 3 2013
4.5
Nov 3 2013
4.5
Version: null
Ron-Magness
Ron-Magness
Dec 4 2012
5.0
Dec 4 2012
5.0
Version: null
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Absolutely Free
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