Find Large Files Eating Your Disk Space with CMD

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Introduction
CMD Method (Quick)
PowerShell Method (Recommended)
Common Space Hogs
FAQ

Introduction

TL;DR

Run in PowerShell: Get-ChildItem -Recurse | Sort-Object Length -Descending | Select-Object -First 20 Name, Length

Your disk is almost full, and Windows is nagging you to clean up. But where are all your gigabytes going?

Third-party tools like WinDirStat work, but they're slow and require installation. The built-in command line can find your largest files in seconds.

CMD Method (Quick)

The classic Command Prompt can list files sorted by size. It's not as powerful as PowerShell, but works on all Windows versions.

1Open CMD as Administrator

Search "cmd" in Start Menu, right-click, and select "Run as administrator". This lets you scan protected folders.

2Run the Size Command

Command Prompt (Admin)

C:\>forfiles /S /C "cmd /c if @fsize GEQ 104857600 echo @path @fsize"

(Lists all files larger than 100MB)

Note

This command is slow on large drives. PowerShell below is much faster.

PowerShell Method (Recommended)

PowerShell is faster and gives you more control over the output format.

Find Top 20 Largest Files

PowerShell

Get-ChildItem -Path C:\ -Recurse -File -ErrorAction SilentlyContinue | Sort-Object Length -Descending | Select-Object -First 20 @{N='Size(GB)';E={[math]::Round($_.Length/1GB,2)}}, FullName | Format-Table -AutoSize

Size(GB) FullName
-------- --------
4.2 C:\Users\You\Downloads\game.iso
2.8 C:\Windows\MEMORY.DMP
1.5 C:\hiberfil.sys
...

Find Files by Extension

Looking for large video files specifically?

PowerShell

Get-ChildItem -Path C:\ -Include *.mp4,*.mkv,*.avi -Recurse -File | Sort Length -Desc | Select -First 10

Common Space Hogs

Downloads Folder

Old installers, ISOs, and zip files pile up here. Check C:\Users\YourName\Downloads

Windows Temp Files

Run %temp% in the Run dialog and delete old files. Also check C:\Windows\Temp

Windows.old Folder

After Windows updates, this can hold 20+ GB of old system files. Use Disk Cleanup to remove safely.

Frequently asked questions

Why does the scan take so long?

Scanning every file on a drive with millions of files takes time. For faster results, target specific folders like C:\Users instead of scanning the entire C:\ drive.

Is it safe to delete large files I find?

Be careful with system files (hiberfil.sys, pagefile.sys, Windows folders). Focus on your personal folders like Downloads, Documents, and game installations.

Can I export the results to a file?

Yes! Add `| Out-File large_files.txt` at the end of any PowerShell command to save results to a text file.

find large filesdisk spacecmd commandswindows cleanupstorage managementpowershell

MD KawsarFounder & CEO of BigiByte. Fiverr Pro and Upwork Top Rated developer who has extracted 15M+ lines of data for clients.