Find out which files use the most space on Windows

Martin Brinkmann
Nov 23, 2012
Updated • Nov 15, 2019
Software, Windows software

The main hard drive of my desktop PC is a 128 Gigabyte Solid State Drive. While that is sufficient for the operating system and applications, it is important to make sure that free space does not drop below the 10% mark as it may affect the performance of the drive and may result in problems when saving data to it.

WizTree is a new portable program from the maker of Bulk Image Downloader, my favorite image downloading application for Windows. The program scans all files and folders of a selected NTFS formated drive and displays its findings afterwards in the application window. A full scan of the Solid State Drive took less than 4 seconds to complete while a scan of a 2 Terabyte platter-based drive completed in less than 9. Impressive values for an application of its kind. The author pulls the information from the Master File Table (MFT) which explains the scanning speed and the limitation to NTFS file systems.

The program displays the total space, used space and free space of the selected drive in absolute terms and in percentages in the header.

A tree view sorted by the largest folders of the drive is displayed automatically after the scan. You can click your way through the structure to find the largest files on the system, or switch to the top 1000 largest files tab instead which displays the largest files in a table.

wiztree large files scanner

The table lists the name of the file or folder, the percentage that it occupies on the hard drive, the total size, items (which is files + folders), files and folders, the last modification date and file attributes. A click on a column header sorts the file and folder list by the value.  You can use it to sort files by last modification date or total number of files for instance.

Sizes are displayed dynamically by default, which means that you see KB, MB, GB and Bytes listed under size. You can change the dynamic size mode so that all sizes are displayed using the same digital information storage format.

You can delete files or folders with a tap on the Delete key after you have selected the items that you want to delete. Hold down the CTRL-key during selection to select multiple items at once.

Wiztree is probably the fastest "large file" scanners for Windows at the moment. What I particularly like about the program apart from its speed is the option to quickly delete files right from the interface, and that it does not lag down the PC in any way during the scan or afterwards when you browse the folder and file listing.

The only downside is that it can only scan NTFS drives at the moment but according to the author other formats may be added in the future as well.

Update: WizTree 2.0 has been released. The new version supports all drive types, not only NTFS drives, a new file search, option to run the program as a normal user and not administrator, and an option to run searches on directories and not drives.

Update 2017: WizTree 3.0 is out. The new version is even faster, comes with a 64-bit executable, and highlights changes made to files directly in the interface.


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  1. arthur said on January 9, 2024 at 9:46 am

    FYI / update of this page ??

    new download page =

  2. Andy said on November 25, 2012 at 5:22 pm

    Giving a shout out to which works fine even though it’s not been updated for a while.

  3. Zeus said on November 23, 2012 at 8:45 pm

    I second SpaceSniffer. I ran it against a few other space programs, and it always came up as the fastest scan time around, outclassic RidNacs and several others.

  4. Patrick said on November 23, 2012 at 8:34 pm

    How about Treesize Free at

  5. anony said on November 23, 2012 at 8:02 pm

    Need to be able to do an inline search and accept double click and explorer context menu, otherwise it’s the fastest of this kind indeed.

    That make me wonder if anyone make use of MFT to make a search/indexer. If it got incorporated to software like locate32…

    1. Whino said on November 25, 2012 at 1:40 pm

      Far as I know, both UltraSearch ( ) and Everything ( ) make user of the MFT for file name searches.

      I prefer Everything, and it is *fast*.

  6. ilev said on November 23, 2012 at 7:17 pm

    I use the portable Largest Files Finder (top 100 files).

  7. Paul B. said on November 23, 2012 at 6:21 pm

    This looks awesome. I have SpaceSniffer, which has a gorgeous visual output, but which is too much of a production to use often.

  8. Helen said on November 23, 2012 at 3:50 pm

    You should have a look at Idoswin Pro. It is a free and complete file explorer that display the file sizes (bytes not percentage) given by Master File Table (MFT) of all folders with subfolders automatically.

  9. lainiwaku said on November 23, 2012 at 2:52 pm

    omg the coincidence i was searching this thing 2 hour ago ^^’

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