9 Free Disk Space Analyzer Tools

I list Disk Savvy as the number one disk space analyzer program because it's both easy to use and full of extremely useful features that are sure to help you free up disk space.

You can analyze internal and external hard drives, search through the results, delete files from within the program, and group files by extension to see which file types are using the most storage.

Another useful feature is the ability to see a list of the top 100 biggest files or folders. You can even export the list to your computer to review them later.

Disk Savvy Review & Free Download

There's a professional version of Disk Savvy available, too, but the freeware version seems 100% perfect. You can install Disk Savvy on Windows 10 through Windows XP, as well as on Windows Server 2016/2012/2008/2003.

WinDirStat is another disk space analyzer tool that ranks right up there with Disk Savvy in terms of features; I'm just not too fond of its graphics.

Included in this program is the ability to create your own custom cleanup commands. These commands can be used from within the software at any time to do things quickly, like move files off the hard drive or delete files of a certain extension that are in the folder you select.

You can also scan different hard drives and folders all at the same time as well as see which file types are using up the most space, both of which are rather unique features not found in all of these disk usage analyzers.

WinDirStat Review & Free Download

You can install WinDirStat in the Windows operating system only.

Another free disk space analyzer, JDiskReport, shows how files are using storage through either a list view like you're used to in Windows Explorer, a pie chart, or a bar graph.

A visual take on disk usage can help you quickly understand how the files and folders are behaving in relation to the available space.

One side of the JDiskReport program is where you find the folders that were scanned, while the right side provides ways to analyze that data. Follow the link below to see my review for specific details on what I mean.

JDiskReport Review & Free Download

Unfortunately, you cannot delete files from within the program, and the time it takes to scan a hard drive seems slower than some of the other applications in this list.

Windows, Linux, and Mac users can use JDiskReport.

The programs mentioned above are useful in different ways because they provide a unique perspective for you to look at the data. TreeSize Free isn't so helpful in that sense, but it certainly provides a feature that's missing in Windows Explorer.

Without a program like TreeSize Free, you really don't have an easy way to see which files and folders are occupying all the disk space. After installing this program, seeing which folders are largest, and which files among them are using up most of the space, is as easy as opening the folders.

If you find some folders or files that you no longer want, you can easily delete them from within the program to instantly free up that space on the device.

TreeSize Free Review & Download

You can get a portable version that runs on external hard drives, flash drives, etc. without installing it to the computer. Only Windows can run TreeSize Free. 

RidNacs is for the Windows OS and is actually very similar to TreeSize Free, but just doesn't have all the buttons that may drive you away from using it. Its clear and simple design makes it more appealing to use.

You can scan a single folder with RidNacs as well as whole hard drives. This is an important feature in a disk analyzer program because scanning an entire hard drive may take a long time when you really just need to see the info for one folder.

RidNacs' functionality is very straightforward so you know exactly how to use it right from the start. Just open the folders like you would in Windows Explorer to see the largest folders/files listed from the top down.

RidNacs Review & Free Download

Due to its simplicity, RidNacs just includes the basic features necessary for what a disk analyzer should have, but clearly, doesn't have all the features you'd find in a more advanced program like WinDirStat from above.

Free Disk Analyzer is a really great free disk space analyzer. Above all, I like it because of how simple and familiar the interface is, but there's also some really useful settings I want to mention.

One option makes the program only search for files if they're larger than 50 MB. If you have no intention deleting files smaller than that, then you can drastically clean up the results list by enabling this.

There's also filtering option so that only music, video, document, archive files, etc. are shown instead of every single type of file. This is useful if you're aware that it's videos, for example, that are consuming the most storage — searching just for those saves time sifting through other file types.

The Largest Files and Largest Folders tabs at the bottom of the Free Disk Analyzer program provide a quick way to go over what's eating up all the storage in the folder (and its subfolders) you're looking at. You can sort the folders by the folder size and location, as well as by the average file size in that folder plus the number of files that the folder contains.

Download Free Disk Analzyer

Though you can't export the results to a file like most disk space analyzers allow, I still highly recommend taking a look at Extensoft's program before you move on to the other applications in this list.

Free Disk Analyzer is available for Windows users only.

Disktective is another free disk space analyzer for Windows. This one is completely portable and takes up less than 1 MB of disk space, so you can easily carry it with you on a flash drive.

Each time Disktective opens, it immediately asks what directory you want to scan. You can pick from any folder on any hard drive that's plugged in, including removable ones, as well as the entire hard drives themselves.

The left side of the program shows the folder and file sizes in the familiar Windows Explorer-like display, while the right side displays a pie chart so you can visualize each folder's disk usage.

Download Disktective

Disktective is easy enough to use for anybody, but there are numerous things I don't like about it: The export to HTML feature doesn't produce a very easy-to-read file, you can't delete or open folders/files from within the program, and the size units are static, meaning they're all either in bytes, kilobytes, or megabytes (whatever you choose).

Most of us are used to viewing the data on our computers in a list view where we open folders to see the files inside. SpaceSniffer works similarly but not in the exact same way, so it may take some getting used to before you're comfortable with it.

The picture here immediately tells you how SpaceSniffer visualizes disk space usage. It uses blocks of varying sizes to demonstrate larger folders/files versus smaller ones, where the brown boxes are folders and the blue ones are files (you can change those colors).

The program lets you export the results to a TXT file or a SpaceSniffer Snapshot (SNS) file so that you can load it up on a different computer or at a later time and see all the same results — this is really handy if you're helping someone else analyze their data.

Right-clicking any folder or file in SpaceSniffer opens the same menu that you see in Windows Explorer, meaning you can copy, delete, etc. The filter feature lets you search through the results by file type, size, and/or date.

Download SpaceSniffer

Note: SpaceSniffer is another portable disk space analyzer that runs on Windows, which means you don't have to install anything to use it. It's around 2.5 MB in size.

I've added SpaceSniffer to this list because it's different than the majority of these other disk space analyzers, so you may find that its unique perspective aids in helping you quickly find what's using up all the storage space.

Folder Size is the simplest program from this entire list, and that's because it has virtually no interface.

This disk space analyzer is useful because Windows Explorer doesn't provide you with the size of a folder you're looking at, but instead just the size of files. With Folder Size, a small additional window displays that shows each folder's size.

In this window, you sort the folders by size to easily see which ones are using the biggest slice of storage. Folder Size does have some settings you can modify like to disable it for CD/DVD drives, removable storage, or network shares.

Download Folder Size

A quick look at the picture here of Folder Size demonstrates that it's nothing like the other software from above. If you don't need charts, filters, and advanced features, but just want to be able to sort folders by their size, then this program will do just fine.