How to Turn On or Off Compact OS in Windows 11

What is Compact OS?

Compact OS squeezes your Windows system files smaller. Think of it like vacuum-sealing your clothes to free up closet space. When you turn it on, Windows keeps your files compressed and continues to save space as it updates them over time.

Learn more about Compact OS from Microsoft

Important Things to Know

• Admin privileges required — You must be logged in as an administrator to make these changes.
• This process takes time — Windows needs a few minutes to compress or uncompress your files, so be patient.

Step 1Check if Compact OS is On or Off

Before you make any changes, it’s smart to see if Compact OS is already running on your Windows 11 computer. Knowing its current status helps you decide if you need to turn it on or off to save disk space.

What happens: A message will appear telling you if Compact OS is on or off.

1. Click the ⊞ Start button.
2. Type Windows Terminal.
3. Right-click it and choose Run as administrator. ⚠️ Admin privileges required
4. In the window that opens, copy and paste this command, then press Enter:
   
   compact /compactos:query
5. Read the message:

   • If it says “Compact OS is enabled.” — it’s turned on.
   • If it says “Compact OS is disabled.” — it’s turned off.
6. Close Windows Terminal when done.

Step 2How to Turn On Compact OS

If you want to free up more storage space on your Windows 11 PC, turning on Compact OS is a great way to do it. This process will compress your system files, making them smaller and saving you gigabytes of disk room.

What happens: Windows will compress your system files, which takes some time.

1. Open Windows Terminal as an administrator (follow Step 1 above). ⚠️ Admin privileges required
2. Copy and paste this command, then press Enter:
   
   compact /compactos:always
3. Wait while Windows compresses your files. This may take several minutes.
4. Close the window when finished.

Step 3How to Turn Off Compact OS

Sometimes you might need to turn off Compact OS, perhaps if you notice performance issues or simply want your files back to their original size. This guide shows you the simple steps to uncompress your Windows system files.

What happens: Windows will uncompress your files back to their normal size, which also takes time.

1. Open Windows Terminal as an administrator. ⚠️ Admin privileges required
2. Copy and paste this command, then press Enter:
   
   compact /compactos:never
3. Wait while Windows uncompresses the files. This can take several minutes.
4. Close the window when done.

Summary

• You must have administrator access to use Compact OS.
• Compact OS saves disk space by squeezing Windows system files smaller.
• Use these simple commands in Windows Terminal:
  • Check status: compact /compactos:query
  • Turn on : compact /compactos:always
  • Turn off : compact /compactos:never
• Be patient — compressing or uncompressing files takes time.
• Always check the status after running a command to make sure it worked.

To manage Compact OS on Windows 11, you’ll need administrator rights. This feature helps save disk space by shrinking your system files, and you can easily check its status, turn it on, or turn it off using simple commands in Windows Terminal.