Windows file management system is complex. When you install a file, the Windows OS will write its data to different storage blocks. The blocks may be sequential or non-sequential. When the file data is not stored in consecutive blocks, Windows may take slightly higher time in reading or modifying it (on user’s or app’s request). Such files will make your system slow. They’re known as fragmented files.

The Microsoft Windows OS comes with a disk defragmenter tool to optimize the hard disk drives, but if you want to try something else, you should install the IOBIT Smart Defrag software on your PC.

Below you’ll find our review of this free software for Windows.

IOBIT SD is free to download program for Windows OS. You can get its installer from the website. I have installed the version 4.3.7 of this software on Windows OS powered Lenovo laptop.

The main window of Smart Defrag application has four tabs to access the Disk, Game, configure boot time defragmentation tools and the action center.

IOBIT smart defrag main window

The 1st tab allows the user to optimize or analyze all partitions created by the Windows OS. It features two buttons, i.e., smart defrag and analyze. When the 1st button is clicked, the software will allow you to choose one of the four optimization methods as shown below:

SD options

The analyze button will make the application analyze each file stored on a partition. After it completes the analysis of the disk, this software will display a map of fragmented, optimized, system files (identified by red, green colors).

If you want to know which files are fragmented, you can change the map view to the details view.

IOBIT smart defrag free download Windows

When the defragmentation process is running, SD will display a progress bar and the time for which the process has been running. After the operation is complete, SD will make the user of fragmentation rate. It will also display a view report button. When the user clicks on this button, a detailed report will be shown in a browser. The report shows the following file data:

  • A number of fragments.
  • Size
  • result
  • full path

Here’s a screenshot of the same:


The defragmented partitions will be highlighted with a green tick mark. An optimized disk will be highlighted with a red tick mark. The user can optimize all the drives at once. To do so, he will have to check the box beside the name of the partition.

The 2nd tab i.e. Game Defrag will display a large button to add a game file (executable). This tool will optimize the game’s performance when you click on the Defrag button.

game defrag

In the 3rd tab, the user can configure the software to optimize the system page, hibernation, MFT and other critical files when Windows starts.

boot time defragmenattion

The Action Center will display a list of free software developed by IOBIT.

sd action center

The Smart Defrag software supports a dark and white theme. To change the interface color, the user must click on the shirt icon (check the title bar).

The Smart Defrag features an options panel in which the user can access its settings window, user manual or check for software updates and seek technical support.

The configuration window has five relevant sections:

User Interface:

settings UI

This interface allows you to:

  • change transparency of the UI.
  • switch to some other language from the default English.
  • Turn on the accessible disk map.

Exclude List:
In this section, the user can add files and folders that the software should ignore when it runs the disk defragmenter tool.

Junk Files cleaner:

junk files cleaner Windows
Useless files stored on your PC may degrade the system’s performance. To get rid of such files, check the Enable junk files module from this section. Smart Defrag features a secure file deletion utility that works automatically in the background. It is disabled by default. The Junk files remover tool allows you to select the objects that you want to be cleaned.

Automatic service:

automatic defrag
Smart Defrag can run in the background as a Windows service. If you want this software to optimize Hard disks automatically when you’re busy with some other application, you must configure this section. Here you can set an idle time for the system, after which the Smart Disk Defragmenter application should optimize the disks. The Automatic service section also features the below necessary options:

  • Turn off the disk defragmenter process when the resource usage hits up to a certain level.
  • Enable schedule and boot time defragmentation.


settings defrag

This is a critical section that allows users to configure the below settings:

  • Stop defrag operation when a power plug is not connected to the laptop.
  • Skip files of a specific size.
  • Activate the silent smart technology for better performance.
  • Stop VSS when NTFS partition is being optimized.
  • Replace the default Windows application with Smart Defrag.



Here you will find options to:

  • Minimize the software to system tray when the user closes the application.
  • Run Smart Defrag software automatically when Windows OS boots.
  • Disable optimization of external USB storage drives.
  • Enable or disable tooltips in the system tray.
My Verdict:

I’m impressed with the free IOBIT Smart Defrag tool. My laptop has 1 TB HDD and 3 NTFS partitions, each with around 250 GB storage space. The partition on which the Windows 10 OS is installed has around 5 GB of fragmented files. Iobit optimized the disk within 2 minutes. The program didn’t affect other applications.


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