Single .ps1 to clean up files stored in Downloads. It removes items opens to view (e.g. JPG and PDF) and Clears Duplicates. Useful for Google Chrome users to clear files downloaded only to view - e.g. PDFs. Based on Winston McMiller Duplicate File Finder and Remover

Start-DownloadsCleanup.ps1

<#
.SYNOPSIS
  Finds and removes file duplicates from the Downloads folder

.DESCRIPTION
  Single .ps1 to clean up files stored in Downloads. It removes items opens to view (e.g. JPG and PDF) and Clears Duplicates. Based on Winston McMiller Duplicate File Finder and Remover

.PARAMETER DownloadPath
 Specifies the folder used to store Chrome's Downloads. Default: %USERPROFIKE%\Downloads

.PARAMETER ViewedFileTypes
 An array of file types that should be treated as viewed files - files opened to view, not to store. These will be removed.
 Default: "*.rdp", "*.tcx", "*.gpx", "*.kml", "*.qif", "*.pdf", "*.png", "*.jpg", "*.jpeg", "*.csv", "*.doc", "*.docx", "*.xls", "*.xlsx"

.INPUTS
  None

.OUTPUTS
  None

.EXAMPLE
.\Start-DownloadsCleanup.ps1 "D:\Downloads"
Run with a specified Download folder, e.g. D:\Downloads

.EXAMPLE
.\Start-DownloadsCleanup.ps1 -DownloadPath "D:\Downloads" -ViewedFileTypes @("*.pdf", "*.png", "*.jpg", "*.jpeg", "*.csv", "*.doc", "*.docx", "*.xls", "*.xlsx")
Run with a specified Download folder, and an Array of view-only file extensions

.LINK
Winston McMiller's original Script:
https://gallery.technet.microsoft.com/scriptcenter/Duplicate-File-Finder-and-78f40ae9

.NOTES
  Version:        1.0
  Author:         Cameron McConnochie
  Creation Date:  17 May 2018
  Purpose/Change: Initial script development

  Based on Winston McMiller Duplicate File Finder and Remover
#>

[CmdletBinding()]
Param(
    [Parameter(Mandatory=$False,Position=1)]
    [string]$DownloadPath = "$($Env:USERPROFILE)\Downloads",

    [Parameter(Mandatory=$False)]
    [string[]]$ViewedFileTypes = @("*.rdp","*.tcx", "*.gpx", "*.kml", "*.qif", "*.pdf", "*.png", "*.jpg", "*.jpeg", "*.csv", "*.doc", "*.docx", "*.xls", "*.xlsx", "*.ics")
)

#Standardise the Path format
$DownloadPath = $DownloadPath.TrimEnd('\')

Write-Host "Clearing Downloads folder $($DownloadPath)" -ForegroundColor Blue

## Remove viewing files
#  Array-ise this as a result of 1 item still needs to be processed (duplicates will never have a single result)
$ViewFiles = @(Get-ChildItem -path "$($DownloadPath)\*" -Include $ViewedFileTypes | Select-Object FullName, Length)

##Remove unique record by size (different size = different hash)
$RUBySize = Get-ChildItem -path $DownloadPath -Exclude $ViewedFileTypes | Where-Object {( ! $_.ISPScontainer)} | Group-Object Length | Where-Object {$_.Count -gt 1} | Select-Object -Expand Group | Select-Object FullName, Length

##Remove unique record by hash (generates SHA-1 hash and removes unique records)
$RUByHash = foreach ($i in $RUBySize) {Get-FileHash -Path $i.Fullname -Algorithm SHA1}

#Handle file dupicates
If (($RUByHash.count -gt 0) -or ($ViewFiles.Count -gt 0)) {
  # Gather File stats
  $ViewSavings = ($ViewFiles | Measure-Object -property length -sum).Sum
  $DupSavings = ($RUBySize |select-Object -Skip 1 | Measure-Object -property length -sum).Sum

  #Output GridView display
  #$RUByHash|Out-GridView  -Title "$Title1 Duplicate Files with a potential  savings of $Savings bytes" -PassThru
  Write-Host "View only files found:" -ForegroundColor Cyan
  $ViewFiles | Format-Table
  Write-Host "Duplicate files found:" -ForegroundColor Cyan
  $RUByHash | Format-Table Path, Hash

  Write-Host "Found data savings of $([math]::Round($ViewSavings/1024/1024,2))MB from viewing files and $([math]::Round($DupSavings/1024/1024,2))MB from Duplicates" -ForegroundColor Green

  #Delete viewing files
  Foreach ($file in $ViewFiles) {Remove-Item -Path $file.FullName -Force}
  Write-Host "$($ViewFiles.Count) viewing files deleted"
  #Delete duplicate files
  $RUByHash|select-Object -Skip 1|Remove-Item
  Write-Host "$($RUByHash.count) duplicate files deleted"
} else {
    Write-Host "No files found that can be deleted"
}