How to Zip and Unzip Files with PowerShell

Before PowerShell 5 this meant .NET calls or a third-party tool. Now it is two cmdlets, and they are the right answer for almost every scripted archive job on Windows.

Zip

# zip the contents of a folder
Compress-Archive -Path "D:\Logs\*" -DestinationPath "D:\Archive\logs.zip"

# overwrite an existing zip
Compress-Archive -Path "D:\Logs\*" -DestinationPath "D:\Archive\logs.zip" -Force

# add to an existing zip instead of replacing it
Compress-Archive -Path "D:\Logs\extra.log" -DestinationPath "D:\Archive\logs.zip" -Update

# a dated archive, which is what most scheduled jobs actually want
$stamp = Get-Date -Format 'yyyyMMdd'
Compress-Archive -Path "D:\Logs\*.log" -DestinationPath "D:\Archive\logs-$stamp.zip"

Unzip

Expand-Archive -Path "D:\Archive\logs.zip" -DestinationPath "D:\Restored"

# overwrite files that are already there
Expand-Archive -Path "D:\Archive\logs.zip" -DestinationPath "D:\Restored" -Force

Leave -DestinationPath off and it extracts into a folder named after the zip, in the current directory.

The Trap: Path vs Path\*

This is the one that surprises people. -Path "D:\Logs" puts the folder inside the zip, so everything ends up nested under Logs\. -Path "D:\Logs\*" puts the folder contents at the root of the zip. Neither is wrong, but they are different, and you usually want the second.

Selective Archiving

Combine it with a pipeline when you want to archive only what matches:

# zip only logs older than 30 days, then delete the originals
$old = Get-ChildItem "D:\Logs" -Filter *.log |
       Where-Object LastWriteTime -lt (Get-Date).AddDays(-30)

if ($old) {
    $stamp = Get-Date -Format 'yyyyMMdd'
    Compress-Archive -Path $old.FullName -DestinationPath "D:\Archive\old-$stamp.zip"
    $old | Remove-Item -WhatIf
}

Related

• Delete Files in PowerShell
• Get a Folder Size in PowerShell
• Format Dates with Get-Date
• PowerShell Complete Guide

If SQL Server is part of your day job, my current work lives over at sqldba.blog: production DBA scripts, an error library and the SSMS guide.