One of PowerShell’s benefits is the ability to manage at scale. Instead of processing one thing at a time, we can manage a bunch of things all at once in the same command.

Get-Childitem c:\work\*.xml |
Where-Object {$_.length -ge 10KB} -pipelinevariable before |
Foreach-Object {
    [xml]$doc = Get-Content $_.fullname
    $doc.InnerXml | Out-File $_.fullname -Encoding utf8
    $new = Get-Item $_.fullname
    Write-Host ("Reduced {0} from {1} to {2} ({3:p2})" -f $before.name,$before.length,$new.length,($new.length/$_.length)) -foreground cyan
}

This code snippet is getting all XML files under C:\Work larger than 10KB and resaving the file with all whitespace stripped out of the XML.