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.

In a Hurry?

Go to details...  Go straight to the Quick Selection Guide


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.


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

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


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


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


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.


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

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

This software review is copy-edited by Victor Laurie. Please help edit and improve this article by clicking here.


analyse disk space, analyze disk space free, get folder size free, free disk analyzer, best free disk analyser, top free disk space analyzer, best free space analysis software, freeware.

Back to the top of the article.


Please rate this article: 

Your rating: None
Average: 3.1 (74 votes)


You forgot the Linux versions!

KDirStat is the program that WinDirStat was cloned from. And, naturally, you don't have to worry about trojans in that.

Baobab is a Gnome app that comes with some distros, like Mint. It's also called "Disk Usage Analyzer". After searching around Gismo's in vain, I discovered I already had it.

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!

I agree
Very simple useful result screen
Very fast


Disk Usage Analyzer: Features: * 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

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

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