Best Free Disk Space Analyzer


One way to find out which files are hogging disk space when your hard drive fills up is to use a specialist utility that displays your disk space usage. There are a number of excellent free utilities that differ mainly in the way the disk space usage is portrayed.

These disk space analysers are basically a graphical representation of the windows explorer tree which includes all folders and files. There are headings above groups of boxes (or shapes), these headings represent folders, while the boxes (or shapes) represent files in these folders. Usually the visual size seems to be directly proportional to the size of the file it represents: allowing people to quickly identify large files that could be wasting space and hurting performance.

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SpaceSnifferSpaceSniffer remains #1 for three simple reasons, first and foremost it's free and second it seems to be far and away the best free space disk analyzer, and thirdly it is standalone ( install).  It only took about a minute to do the whole drive.

It can display free space and unknown space. The program reported the space as:  Free 160.1 GB, Used 119.1 GB. The "levels of detail" is button selected (8 levels). The "Go home" button takes you back to master display. You can drill down by double clicking on an area.

The default colours are: drive (orange), free space (green), folders (skin tone), unknown space (gray) and file (blue). All are changeable. Can change contrast, border contrast and a hi-light halo level (when a file is selected or mouse is hovered). There is an export function that will give you either the file list in the selected directory or stats about that directory: this did not seem too useful.


WinDirStat WinDirStat is another outstanding program. Different languages can be installed (Czech, German, Spanish, Finnish, French, Hungarian, Italian, Dutch, Polish, Russian and Estonian)

It reported 279.5 GB total, 158.2 GB Free. It took about about 20 sec to scan the drive. Shows files types and the size they consume. The lower half of the windows shows a coloured picture of file types (tree map - can be turned off).  Click in this area and the file is highlighted above. Each file's relative size is also displayed in the lower window.  A click on the file type window highlights all the locations on the disk in the lower window.  Once the amount of space consumed by the file type drops, all other file types a lumped together.  Clicking in the file list, say on a directory, highlights the location in the lower window. 

Options include: open explorer at the selected location; cmd prompt at the selected location; delete and erase; properties and empty the recycle bin. You can also zoom in and out of the tree map; select the parent directory and there is a good help feature that is built-in.


Folder Size Scan Window

Folder Size from MindGems Software installed fine, then tried to go to the website - problematic if you're not connected.  It took a few minutes or so to scan the drive. Has different units (B, KB, MB, or GB). Displayed drive size as 122.62 GB (131,659,620,315). Tried to download a flash player for the chart display (again problematic if you're not connected). Can scan a folder and shows size, percent, number of files, number of sub-folders, dates, attribvutes and owner. Able to 'drill down' by double clicking on a folder name. Clearly shows the page.sys file when "home".

View window in lower right summarises all the drive. C reported as 279.45 GB, 121.25 GB free and 158.20 GB used.


GetFolderSize adds a right click to the explorer context (and Xplorer2) to get folder size.  Reports the number of files and sub-directories giving the size (bytes, KB, MB, or GB with or without two decimal display), percent, number of files and number of folders. 

What to display is selectable by button presses on the main screen. The largest files can be display at the click of a button (displayed pagefile.sys). A file list for any directory is activated by a button click. The display is highly selectable, all by button clicks. These are the results for the drive: Used 121.25 GB (130,189,717,504), Free 158.20 GB (169,868,464,128). Cluster size 4.00 KB, and a Total  279.45 GB (300,058,181,632). 

Nice program, but no nice visual display of space consumed on the drive. Files can be deleted from within. You can search for a folder name (not file name). Column width can be optimised for the display. Languages are German and English. And it took a minute or so to scan the drive, so it's not the fastest!


Glary Utilities has a disk analysis section as part of the many tools (click on Modules on the main screen, then Disk Analysis). A very fast scan. Shows file types (e.g. how much space your mp3's take up) and shows large files. Click on the file type and a list of files is shown. Tool bar has links to cmd prompt, Explorer, and shows the properties of an item selected (file or folder). Very useful set of utilities in general.


RidNacs adds a utility command to the windows explorer context menu (Analyse disk space with RidNacs). And it can open as a program in its own right. Very fast scan. Reported 158 GB Free, and 122 GB Used. 

It shows directories and their size. Nice bar chart display of same with the number of files in each directory. Can drill down by double clicking on the item of interest. Can open a selected directory in explorer. You can save the results as a csv file and has an option to group files smaller than a selectable size (1 MB and above).  Two rounding options for files size (explorer like or Banker's rounding. Languages are either English or German. The bar color is selectable from a small drop down list.


Scanner is a basic, quick, no-frills drive space analysis program. It has a single window display that shows a tree-fan graphic, drive selection buttons, a button for emptying the Recycle Bin and one that pops up the Control Panel Uninstall Programs window. It starts scanning immediately when started, so be prepared for the delay during startup. One unusual feature of the program is that the window cannot be resized by clicking and dragging the borders. Instead, there are small '+' and '-' icons next to the drive selection buttons that are used to make the window incrementally bigger or smaller.

The prominent tree-fan graphic is browsable by clicking on the elements of the tree. There is no built-in file explorer, but right-clicking on an element in the graphic pops up a menu that includes an option to open it in Windows. The right-click menu also includes options for deleting items, as well as hiding or zooming in on items in the tree. The 'Rescan Folder' button rescans from the current folder level for speedy updates after making changes.

This is a standalone program with a single, small executable file, so it is easily portable. It can be integrated with the Windows Explorer context menu by running a registry setup file that comes with the program, but the REG file needs to be modified with the program location before running it. Manually modifying the registry like this is probably not something for the casual user. A text help file is included that is worth reading to get details on using the program, including known bugs and limitations.

Scanner is small and quick with a clean, but non-standard interface. However, it lacks some features that are common in other utilities in this category.


JDiskReport Screen CaptureJDiskReport is a Java disk space analysis program with an interesting collection of features for presenting the analysis results. It does require Java installation on the computer to use it, but this makes it useable on systems where you may be restricted from running other executable programs. For example, my work computer doesn't allow me to run programs that aren't installed by our I/T group, but I can run Java applications. The installer version of the download includes an option for adding an Explorer context menu entry. There is a separate portable version download.

After a scan is complete the program displays a folder view and a large, tabbed graphic pane. You can move down in the results levels by either selecting a folder or clicking on elements of the graphic. The graphic window display options are pie, ring and bar chart. A file view is also selectable for display in the graphic window. Other tabs take you to a text display of the 'Top 50' by largest, oldest or newest, and graphical displays of size distribution, date modified or file types. The right-click menu includes options for opening Explorer, copying text displays to the clipboard and printing. The scan results can be saved and retrieved, which is handy considering that scan speed is not one of the program features. A comprehensive help file is accessible from the help menu.

The program is easy to use and has good data presentation options. The problems are its poor scanning speed and limited options for interacting with the file system. The developer is upfront about the limitations of the software, which is refreshing, and clearly describes them in the help file.

JDiskReport is visually attractive, includes very useful display options and will run on just about any computer with Java. However, its lack of scanning speed limits it to casual use.

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
Treemapping technology, filters enabled, changeable color configuration. Standalone program with no install. Manuals included.
No Scroll Zoom or stats tab.
1501 KB
Unrestricted freeware
This product is portable.
Win 98 - Win 7
Runs as a stand-alone program on a user's computer
Tree view and other visual presentations.
Rectangular treemaps not squarified.
645 KB
Unrestricted freeware
Win 95 - Win 7
Folder Size
Runs as a stand-alone program on a user's computer
Highly versatile with comprehensive reports and pie chart mapping
Nothing major
2.37 MB
Unrestricted freeware
Windows 95/98/ME/NT4/2000/XP/2003/Vista/Windows 7
Runs as a stand-alone program on a user's computer
Lots of options, quite fast
No graphical display of space consumed
2.38 MB
Unrestricted freeware
Windows XP/Vista/7
Glary Utilities
Runs as a stand-alone program on a user's computer
Lots of other goodies in this package.
Not specifically designed to do the job.
11.8 MB
32 bit but 64 bit compatible
Unrestricted freeware
Windows XP/2000/Vista/7
Runs as a stand-alone program on a user's computer
Fast and can easily drill down.
Website is mostly in German.
105.8 KB
Unrestricted freeware
Windows All
Runs as a stand-alone program on a user's computer
Lovely visuals. Standalone program with no install.
User interface doesn't follow usual Windows functional style.
243 KB
Unrestricted freeware
Windows XP and above
Runs as a stand-alone program on a user's computer
Visually attractive, includes very useful display options and will run on just about any computer with Java.
Lack of scanning speed limits it to casual use.
Unrestricted freeware
A portable version of this product is available from the developer.


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by v.laurie on 26. March 2014 - 17:41  (115319)

There is a Trojanized version of WinDirStat out on the Internet.
Be very careful which download site you use and check with VirusTotal.

by sicknero on 2. January 2014 - 9:48  (113345)

My find of the month re space analysis is definitely Wiztree. It works by reading the MFT and thus will give you results in just a few seconds even on large external drives.

The only downside is that because of the way it works it's only for NTFS formatted volumes. It also has only a list view - no pie charts or coloured graphs here - but man, it is really really quick!

by g2mXagent on 30. July 2013 - 18:54  (109776)

i use "TreeSize Free", simple and useful.

by Panzer on 5. June 2013 - 7:45  (108292)

Disk Usage Analyzer:


* Finds largest files within selected drive or folder
* Finds largest folders by folder size, average file size, or number of files
* Presents information visually via graphs
* Looks and feels like part of Windows
* Provides sorting functionality by displayed columns

by tratak on 20. February 2013 - 9:28  (105571)

This is, in my opinion, the best disk space analyzer:

by PhiloVance on 8. March 2013 - 0:21  (106035)

Sequoiaview has one drawback. Maybe I'm dense, but I can only get it to work on the C disk.

by RCL on 24. February 2013 - 14:20  (105713)

The graphical results display is very similar in appearance to WinDirStat's. I will have a look. Thanks!

by Panzer on 11. February 2013 - 8:51  (105295)

"... WizTree is a disk space analyzer. It scans your entire hard drive and shows you which files and folders are using the most disk space. It does this VERY QUICKLY. In fact, we believe WizTree to be the fastest application of this type in the world! Use the information WizTree provides to quickly locate and remove "space hogs" from your hard drive ...":

by RCL on 12. February 2013 - 0:31  (105318)

I will have a look. Thanks!

by Marky (not verified) on 13. November 2012 - 17:59  (102261)

FS-Inspect ->

by Duiwels (not verified) on 23. September 2012 - 10:01  (99633)

Treesize Free from JAM Software:

by Anonymous22 (not verified) on 11. September 2012 - 16:13  (99113)

SpaceSniffer crashes (Win 7 x64) when I delete all Files within a folder using it... what a great tool....

by Zangobanana (not verified) on 10. September 2012 - 1:26  (99024)

and what about the Sysinternals "DU" ? :)

i love it

by Kbarb (not verified) on 26. July 2012 - 18:28  (96700)

JDiskReport (free) looks pretty good.
I had to tell it where Java is, but other than that it ran fine - seemed very useful.

by OpenZero on 22. July 2012 - 13:21  (96508)
by RemoJoe (not verified) on 18. May 2012 - 14:09  (93670)

Regarding SpaceSniffer Export reports:
These can be very useful if you are recovering data from from someone else's damaged or disorganized system. For example, locate all PowerPoints or family JPG's or whatever for a user who is moving to a new computer. Maybe the last sentence of the review needs to be amended.

On a related topic concerning file structure reorganization:

Any hints about file sorting software that would automatically gather files into folders by file type? Only thing I have discovered so far is PySort:

by ZenHeur (not verified) on 15. May 2012 - 14:57  (93496)

Anybody having trouble with launching spacesniffer on a 64-bit windows 7 system?

First the extracted file does not have the .exe extension so I added it. The when I launch I get a message "The version of this file is not compatible with the version of Windows you're running".

So now what?

by gkramer on 16. May 2012 - 9:10  (93542)

I've just downloaded the same version and installed it on my Win7 PC (not 64 bit though) and had it work successfully.

A couple of notes:

1) You must "Run as Administrator" to get it to work properly
2) The Zip file set had an exe file (and 4 others), is your suffix suppressed?
3) "SpaceSniffer has been tested on Windows 2000 SP4/XP/Vista/7 (32/64bit) systems. Currently, SpaceSniffer code is 32 bit, but when runned under a 64 bit environment it asks
to the O.S. the permission to examine also the 64 bit O.S. folders, so the result is correct
even under 64 bit systems."

by Odinbc on 20. March 2012 - 18:46  (90883)

I would be careful installing GetFolderSize. This program has been known to offer to install "Relevant Knowledge". I would not download from the SnapFile link mentioned in the article above.

I recommend going to the authors web site and downloading, GetFoldersize
(Portable Edition) ZIP. Either way make sure you read all of the software disclaimer.

by gkramer on 22. March 2012 - 17:48  (90984)

thanks for the warning

by Gadgeteer (not verified) on 15. February 2012 - 6:34  (88896)

Thank you so much for these reviews

The latest version of Spacesniffer v1.1.4 does zoom, as well as colour filters, and I went straight ahead and integrated it into explorer.

I used to prefer pie chart displays, but I understand the boxes now (thanks to the funky mouse animations and highlighting), plus I actually appreciate the toned down colour schemes.

by gkramer on 15. February 2012 - 16:12  (88907)

I've updated some of the details in the Quick Selection Guide

by Anonymous - anon (not verified) on 18. November 2011 - 18:41  (83498)

Excellent article.

That's what i'd like to see avail for all sections on TSA -

1) portable option?
2) any dependencies?
3) does it try to phone home?

by MidnightCowboy on 19. November 2011 - 5:09  (83527)

The possibilities relating to point 3) are too wide ranging. There may be a connection from the installer for instance which will be different if users choose CNet for their download, instead of the link provided here. Also, component changes can be made during an update which has been initiated either automatically or manually.

The safest policy is to assume that all products will phone home either on install or at some point thereafter. A good firewall will produce an alert for these allowing you to block them if desired. Be aware though that many of the modern third party firewalls contain whitelisted "trusted" vendor lists, so products from these vendors will not be blocked from connecting unless this setting is disabled, or the list edited. Privatefirewall now offers the facility to delete the whole list with a single click should users wish to assign only their own chosen vendors to a trusted list.

by Anupam on 18. November 2011 - 18:48  (83499)

First two are already covered in all articles.

by BrianG (not verified) on 17. November 2011 - 20:16  (83450)

Is anyone aware of a drive space analysis tool that can save a baseline map of the drive and then compare subsequent scans to that baseline to see what has changed? There may also be file change monitoring options out there as well, but I haven't looked. I really need to find out what file(s) is/are growing on my computer.

by mmaker1234 on 2. January 2014 - 9:44  (113344)

The Xinorbis site states that "The Folder History feature allows the user to see and compre the results of any previous scan on a specific folder."

by db2man on 10. December 2011 - 5:46  (84747)

Exactly what I have been looking for. No luck yet.

by Mark Z (not verified) on 12. September 2011 - 17:03  (79490)

Very nice freeware disk analyzer for Win:

Better Directory Analyzer (

Drag'n'drop interface, nice visualization.

by gkramer on 15. September 2011 - 13:13  (79654)

In order to run Better Directory Analyzer on your computer, you must have .NET Framework 3.5 installed. Some users may not like that (Win7 already has it, so for those users it's not an issue).

I installed it on my Win7 laptop and had a look. It does not have the visual aids the others programs mentioned above have, but it does have similar details in tabular form that can be date and/or size refined. The "find duplicate files" option is nice and ran quite quickly on one of my directories (1.19 Gb and 6300 file) finding several duplicates (didn't say how many though).

It does not scan some system files, so you will not see how much space they occupy.

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