How to Check SMB Compression in Windows 11

Wednesday, September 30, 2026

Learn how to check SMB compression in Windows 11 using PowerShell, inspect compression settings, and troubleshoot SMB transfer performance.

SMB compression is a Windows 11 feature that can reduce the amount of data transferred over a network when copying files through Server Message Block (SMB). It can be particularly useful when transferring large files over slower, congested, or bandwidth-limited network connections.

Instead of requiring users or applications to compress a file manually before copying it, SMB can request compression during the network transfer. This can reduce network bandwidth usage, although compression can also increase CPU usage during the transfer.

Windows 11 provides PowerShell commands that allow you to inspect SMB compression settings on both the client and server sides. You can also check whether individual SMB shares are configured for compression and configure mapped SMB drives to request compressed traffic.

In this guide, you will learn how to check SMB compression in Windows 11, understand the main compression settings, inspect SMB shares, configure compression requests, test compression with file-copy tools, and troubleshoot performance or compatibility problems.

What Is SMB Compression?

SMB compression allows files to be compressed while they are transferred through an SMB connection. The sender compresses eligible SMB data before transmission, and the receiving side decompresses it.

This can be useful because the amount of network traffic may be reduced without requiring the original file to be permanently compressed on disk.

For example, suppose a Windows 11 computer needs to copy a large file to a network share. Without SMB compression, the file is transferred in its normal form. With SMB compression requested and supported, the SMB protocol can compress the data during the transfer.

The feature is most useful when network bandwidth is a limiting factor. Microsoft notes that SMB compression can be particularly effective on lower-bandwidth networks, while a very fast, uncongested network may see less practical benefit because CPU overhead can offset some of the network advantage.

Why Should You Check SMB Compression?

Checking SMB compression can be useful when you are investigating network file-transfer performance or planning a Windows 11 file-sharing configuration.

Determine whether SMB compression is available and configured.
Check whether the SMB client requests compression.
Check whether the SMB server requests compression.
Check whether a specific SMB share has compression enabled.
Identify whether compression has been disabled.
Test compression with large file transfers.
Reduce network bandwidth consumption when appropriate.
Investigate CPU usage during SMB transfers.

Compression should not automatically be considered a performance improvement in every environment. Network speed, CPU performance, file type, storage speed, and network congestion all affect the result.

SMB Compression vs SMB Encryption

SMB compression and SMB encryption have completely different purposes.

Feature	Main Purpose
SMB Compression	Reduce the amount of data transferred over the network.
SMB Encryption	Protect SMB data from being read during network transmission.
SMB Signing	Help protect SMB message integrity and detect tampering.
SMB Multichannel	Allow SMB to use multiple network paths when supported.

These features can be used in the same SMB environment. For example, a file server can use SMB encryption for confidentiality while SMB compression reduces the amount of data transferred.

For more information about SMB encryption, see How to Check SMB Encryption in Windows 11.

SMB Compression Requirements

SMB compression is supported by Windows 11 and Windows Server versions documented by Microsoft. The feature was introduced for Windows 11 and Windows Server 2022, with later updates adding additional controls and algorithms.

Microsoft documents several compression algorithms, including XPRESS, XPRESS Huffman, LZNT1, PATTERN_V1, and LZ4 on supported newer systems.

Windows 11 24H2 and Windows Server 2025 introduced LZ4 support for SMB compression, while the exact algorithms available depend on the Windows version on both sides of the connection.

The SMB client and server negotiate compression capabilities rather than simply assuming that every SMB connection supports every compression algorithm.

How to Check SMB Client Compression Settings

The SMB client controls outgoing SMB connections from your Windows 11 computer. You can inspect its complete configuration with:

Get-SmbClientConfiguration

Because the full output contains many properties, you can focus on compression-related settings:

Get-SmbClientConfiguration |
Select-Object RequestCompression, DisableCompression

Depending on your Windows version, additional compression-related properties may be available.

To see the complete configuration in an easier-to-read format:

Get-SmbClientConfiguration | Format-List *

What Does RequestCompression Mean?

RequestCompression controls whether the SMB client is configured to request compression when transferring data.

You can check it with:

Get-SmbClientConfiguration |
Format-List RequestCompression

A result such as:

RequestCompression : True

indicates that the client is configured to request SMB compression.

This does not mean that every SMB transfer will necessarily be compressed. The remote SMB server and the connection must support the feature, and other compression controls can affect the result.

What Does DisableCompression Mean?

DisableCompression is used to prevent SMB compression from being used by the SMB client.

Check the setting with:

Get-SmbClientConfiguration |
Format-List DisableCompression

If compression is disabled, enabling a compression request elsewhere may not produce the expected result.

When troubleshooting, check both RequestCompression and DisableCompression instead of looking at only one property.

How to Check SMB Server Compression Settings

If your Windows 11 computer is also acting as an SMB server, you can inspect the server configuration with:

Get-SmbServerConfiguration

To focus on compression:

Get-SmbServerConfiguration |
Select-Object RequestCompression, DisableCompression

You can also display the complete configuration:

Get-SmbServerConfiguration | Format-List *

The server-side configuration is important when Windows 11 hosts shared folders that other computers access.

How to Check SMB Share Compression

SMB compression can also be configured at the individual share level.

To list the SMB shares on a Windows 11 computer:

Get-SmbShare

To inspect the compression setting for all shares:

Get-SmbShare |
Select-Object Name, Path, CompressData

Example output:

Name        Path                  CompressData
----        ----                  ------------
Documents   C:\Shares\Documents   True
Projects    D:\Shares\Projects    False
Media       D:\Shares\Media       False

The CompressData property indicates whether compression is configured for the share.

How to Check One SMB Share

If you only need to inspect one share, specify its name:

Get-SmbShare -Name "Documents" |
Select-Object Name, Path, CompressData

You can also view the complete share configuration:

Get-SmbShare -Name "Documents" | Format-List *

This can be useful when a particular shared folder behaves differently from other shares on the same computer.

How to Enable SMB Compression on a Share

Microsoft supports configuring an SMB share to request compression by using the CompressData parameter.

For an existing share, use:

Set-SmbShare -Name "Documents" -CompressData $true

Then verify the setting:

Get-SmbShare -Name "Documents" |
Select-Object Name, Path, CompressData

You should see:

CompressData : True

This configuration requests compression for traffic involving that share. The actual transfer still depends on SMB negotiation and the configuration of the client and server.

How to Create a New SMB Share With Compression

If you are creating a new Windows SMB share, Microsoft supports the -CompressData parameter with New-SmbShare.

New-SmbShare -Name "Documents" -Path "C:\Shares\Documents" -CompressData $true

After creating the share, verify it:

Get-SmbShare -Name "Documents" |
Select-Object Name, Path, CompressData

This is useful when building a new file-sharing server and you already know that the workload benefits from compression.

How to Request Compression on a Mapped SMB Drive

Windows also supports requesting compression when creating an SMB mapping.

For example:

New-SmbMapping -LocalPath "Z:" -RemotePath "\\SERVER01\Documents" -CompressNetworkTraffic $true

This creates an SMB mapping that requests compressed network traffic.

You can use this approach when you want compression for a particular mapped connection rather than changing the behavior of every SMB client connection.

Request SMB Compression With NET USE

Windows also provides a command-line option for requesting compression when mapping an SMB share with NET USE.

NET USE Z: \\SERVER01\Documents /REQUESTCOMPRESSION:YES

This can be useful in scripts or environments where SMB mappings are created from Command Prompt rather than PowerShell.

Request SMB Compression With Robocopy

For specific file-copy operations, Robocopy supports the /COMPRESS option.

ROBOCOPY C:\Source \\SERVER01\Documents /E /COMPRESS

This allows you to request SMB compression for the copy operation rather than changing the general SMB client configuration.

This can be useful for testing because you can compare a transfer with compression requested against a normal transfer.

How to Request SMB Compression by Default

If you want the SMB client to always attempt compression, Microsoft documents the following PowerShell command:

Set-SmbClientConfiguration -RequestCompression $true

Afterward, verify the configuration:

Get-SmbClientConfiguration |
Format-List RequestCompression, DisableCompression

Remember that requesting compression is not the same as guaranteeing that every byte of every transfer will be compressed. The remote server must support the feature and the SMB connection must be able to negotiate it.

How to Disable SMB Compression on the Client

If you need to prevent the SMB client from using compression, Microsoft documents:

Set-SmbClientConfiguration -DisableCompression $true

After making the change, verify the configuration:

Get-SmbClientConfiguration |
Format-List RequestCompression, DisableCompression

Use this setting carefully because disabling compression may increase network traffic for workloads that would otherwise benefit from it.

How to Request SMB Compression on the Server

Windows also supports configuring an SMB server to always attempt compression.

Use:

Set-SmbServerConfiguration -RequestCompression $true

Then verify:

Get-SmbServerConfiguration |
Format-List RequestCompression, DisableCompression

This is useful for Windows systems that provide shared folders to multiple clients.

How to Disable SMB Compression on the Server

If you need to prevent the SMB server from using compression, Microsoft documents:

Set-SmbServerConfiguration -DisableCompression $true

Verify the setting afterward:

Get-SmbServerConfiguration |
Format-List RequestCompression, DisableCompression

Changing server-wide SMB behavior can affect multiple users and applications, so test the effect before deploying the change broadly.

How to Test SMB Compression

Configuration values alone do not tell you whether compression is producing a useful real-world performance improvement.

A practical test is to copy a large file over an SMB connection and compare the transfer with compression requested and without compression.

For example, you can use Robocopy:

ROBOCOPY C:\TestData \\SERVER01\Documents testfile.bin /J /COMPRESS

Then compare it with a transfer without the compression request:

ROBOCOPY C:\TestData \\SERVER01\Documents testfile.bin /J

Record:

Transfer time.
Average network throughput.
CPU usage on the client.
CPU usage on the server.
Network utilization.
Storage activity.

For a meaningful comparison, use the same file, same source, same destination, and similar network conditions.

Which Files Benefit Most From SMB Compression?

Compression is most useful when the data itself can be compressed effectively.

Files containing repetitive or uncompressed data may benefit significantly. Examples can include some disk images, database exports, logs, raw data, and other files with substantial compressible content.

Files that are already highly compressed may provide much less benefit.

JPEG images are already compressed.
MP4 video is generally already compressed.
ZIP archives are already compressed.
Many modern document formats already use compression internally.

For these file types, SMB compression may consume CPU resources without substantially reducing the amount of data transferred.

SMB Compression and Network Speed

The usefulness of SMB compression depends heavily on the network.

On a congested or bandwidth-limited connection, reducing the amount of data transmitted can improve effective transfer performance.

On a very fast network with plenty of unused bandwidth, compression may provide less practical benefit. In some situations, the additional CPU processing can offset the time saved by sending fewer bytes.

This is why SMB compression should be measured rather than assumed to be faster in every environment.

SMB Compression and SMB Multichannel

SMB compression and SMB Multichannel solve different problems.

SMB Multichannel allows SMB to establish multiple network channels when supported. SMB compression reduces the amount of data that needs to be transferred.

They can be used together in an environment that supports both features.

You can inspect SMB Multichannel connections with:

Get-SmbMultichannelConnection

For a complete guide, see How to Check SMB Multichannel in Windows 11.

SMB Compression and SMB Encryption

SMB compression can also be used in environments where SMB encryption is enabled.

Encryption protects the confidentiality of SMB traffic, while compression reduces the amount of data transferred.

If you are troubleshooting a performance problem on an encrypted SMB connection, test the complete workload rather than assuming that compression will automatically compensate for encryption overhead.

For the encryption side of the configuration, see How to Check SMB Encryption in Windows 11.

How to Troubleshoot SMB Compression Problems

If SMB compression does not appear to work as expected, start by checking the client:

Get-SmbClientConfiguration |
Select-Object RequestCompression, DisableCompression

Then check the server:

Get-SmbServerConfiguration |
Select-Object RequestCompression, DisableCompression

If a specific share is involved, inspect it:

Get-SmbShare |
Select-Object Name, Path, CompressData

Next, check the SMB dialect of the active connection:

Get-SmbConnection |
Select-Object ServerName, ShareName, Dialect, NumOpens

The negotiated SMB dialect matters because SMB compression is associated with SMB versions that support the feature.

If the remote system is a NAS or third-party SMB server, consult its documentation to determine whether SMB compression is supported.

Common SMB Compression Problems

Several situations can make SMB compression appear ineffective.

The remote SMB server does not support SMB compression.
Compression is disabled on the client.
Compression is disabled on the server.
The share is not configured to request compression.
The files are already highly compressed.
The network is fast enough that compression provides little benefit.
CPU usage becomes the limiting factor.
The test does not use comparable network conditions.

Checking the client, server, share, and actual workload separately makes troubleshooting much easier.

How to Compare SMB Compression Settings Between Computers

If you manage multiple Windows 11 systems, exporting the configuration can help identify differences.

For example:

Get-SmbClientConfiguration |
Select-Object RequestCompression, DisableCompression |
Export-Csv "$env:USERPROFILE\Desktop\smb-compression-client.csv" -NoTypeInformation

For server configuration:

Get-SmbServerConfiguration |
Select-Object RequestCompression, DisableCompression |
Export-Csv "$env:USERPROFILE\Desktop\smb-compression-server.csv" -NoTypeInformation

You can compare these files between computers to identify configuration differences.

SMB Compression vs File Compression

SMB compression is not the same as creating a ZIP or 7z archive.

SMB Compression	File Compression
Occurs during network transfer.	Usually creates a compressed file or archive.
Designed to reduce network traffic.	Designed to reduce file storage size or package files.
Does not require changing the original file.	Usually creates a separate compressed representation.
Can be negotiated between SMB endpoints.	Requires a compression application or archive format.

Therefore, SMB compression is useful when the goal is to optimize network transfer rather than permanently compress the source files.

Useful SMB Compression Commands

Command	Purpose
`Get-SmbClientConfiguration`	View SMB client compression settings.
`Get-SmbServerConfiguration`	View SMB server compression settings.
`Get-SmbShare`	View SMB shares and CompressData settings.
`Get-SmbConnection`	View active SMB client connections and negotiated dialects.
`Set-SmbClientConfiguration`	Configure SMB client compression behavior.
`Set-SmbServerConfiguration`	Configure SMB server compression behavior.
`Set-SmbShare`	Configure compression for an SMB share.
`New-SmbMapping`	Create an SMB mapping with compression requested.
`ROBOCOPY /COMPRESS`	Request SMB compression for a Robocopy operation.

Frequently Asked Questions

What is SMB compression in Windows 11?

SMB compression allows Windows to compress eligible SMB data during network transfers, reducing the amount of data that must travel across the network.

How do I check SMB compression in Windows 11?

Use Get-SmbClientConfiguration for client settings, Get-SmbServerConfiguration for server settings, and Get-SmbShare to inspect compression settings on individual shares.

What does RequestCompression mean?

RequestCompression controls whether an SMB client or server is configured to request compression.

What does DisableCompression mean?

DisableCompression prevents SMB compression from being used by the corresponding SMB client or server configuration.

What does CompressData mean?

CompressData is an SMB share property that controls whether compression is configured for that share.

Does SMB compression make file transfers faster?

It can, particularly when network bandwidth is limited or congested. However, compression consumes CPU resources, so the actual result depends on the network, CPU, storage, and file type.

Does SMB compression work with SMB encryption?

SMB compression and encryption are separate features and can be used in the same SMB environment. Compression reduces network traffic, while encryption protects the confidentiality of the transmitted data.

Does Windows 11 24H2 support SMB compression?

Yes. Windows 11 supports SMB compression, and Microsoft documents LZ4 support beginning with Windows 11 24H2.

Should I enable SMB compression everywhere?

Not necessarily. Test the workloads first. Compression can be beneficial on bandwidth-limited networks but may provide little benefit on very fast networks or highly compressed files.

Related Windows 11 SMB Guides

Final Thoughts

SMB compression can be a useful Windows 11 networking feature when large amounts of data need to move across a bandwidth-limited or congested network. PowerShell provides several ways to inspect and configure the feature at the client, server, and individual share levels.

The most useful commands to remember are Get-SmbClientConfiguration, Get-SmbServerConfiguration, Get-SmbShare, and Get-SmbConnection.

When evaluating SMB compression, do not look only at the configuration. Test real file transfers and compare network utilization, transfer time, CPU usage, and file types. A configuration that helps one network may provide little benefit on another.

For a complete SMB troubleshooting workflow, combine compression checks with SMB encryption, SMB signing, SMB dialect, SMB Multichannel, share permissions, network profile, firewall settings, and active SMB connections.