PowerShell Script to Compress Files Quickly

Use Compress-Archive -Path 'files' -DestinationPath 'archive.zip' in PowerShell to compress files into a ZIP archive quickly.

Examples

InputCompress-Archive -Path 'C:\Docs\file.txt' -DestinationPath 'C:\Docs\file.zip'

OutputCreates file.zip containing file.txt in C:\Docs

InputCompress-Archive -Path 'C:\Images\*' -DestinationPath 'C:\Backup\images.zip'

OutputCreates images.zip containing all files in C:\Images

InputCompress-Archive -Path 'C:\EmptyFolder\*' -DestinationPath 'C:\Backup\empty.zip'

OutputCreates empty.zip but it will be empty if no files exist

How to Think About It

To compress files in PowerShell, identify the files or folder path you want to archive, then use the built-in Compress-Archive cmdlet specifying the source and the destination ZIP file. This cmdlet handles creating the ZIP file and adding the files automatically.

Algorithm

1

Get the path of files or folder to compress

2

Set the destination path for the ZIP archive

3

Use the Compress-Archive cmdlet with source and destination

4

Verify the ZIP file is created with the expected contents

Code

powershell

Compress-Archive -Path 'C:\Example\*' -DestinationPath 'C:\Example\archive.zip'
Write-Output "Files compressed to archive.zip"

Output

Files compressed to archive.zip

Dry Run

Let's trace compressing all files in C:\Example to archive.zip

1

Identify files

Files in C:\Example: file1.txt, file2.txt

2

Run Compress-Archive

Compress-Archive -Path 'C:\Example\*' -DestinationPath 'C:\Example\archive.zip'

3

Output confirmation

Write-Output "Files compressed to archive.zip"

Step	Action	Value
1	Files found	file1.txt, file2.txt
2	ZIP created	archive.zip with file1.txt, file2.txt
3	Output	Files compressed to archive.zip

Why This Works

Step 1: Using Compress-Archive

The Compress-Archive cmdlet is built into PowerShell and compresses files or folders into a ZIP file.

Step 2: Specifying paths

You provide the source files with -Path and the ZIP file location with -DestinationPath.

Step 3: Output confirmation

Using Write-Output prints a message confirming the compression completed.

Alternative Approaches

Using .NET System.IO.Compression

powershell

[System.IO.Compression.ZipFile]::CreateFromDirectory('C:\Example', 'C:\Example\archive.zip')
Write-Output "Compressed using .NET method"

This method uses .NET directly and can compress entire folders but requires PowerShell 5+ and the assembly loaded.

Using 7-Zip command line

powershell

Start-Process -FilePath '7z.exe' -ArgumentList 'a', 'C:\Example\archive.zip', 'C:\Example\*' -Wait
Write-Output "Compressed using 7-Zip"

Requires 7-Zip installed; offers more compression options but adds external dependency.

Complexity: O(n) time, O(n) space

Time Complexity

The time depends on the number of files n being compressed because each file is read and added to the archive.

Space Complexity

The space needed is proportional to the total size of files compressed, as the ZIP archive stores all data.

Which Approach is Fastest?

Using Compress-Archive is fast and simple for most cases; .NET methods may be slightly faster for large folders, while 7-Zip offers better compression but requires extra setup.

Approach	Time	Space	Best For
Compress-Archive cmdlet	O(n)	O(n)	Simple built-in compression
.NET ZipFile method	O(n)	O(n)	Compressing entire folders programmatically
7-Zip command line	O(n)	O(n)	Advanced compression with external tool